Could you talk to some of the key differences between Japanese and Western conceptions of the self, and how they impact privacy?
My thoughts on this issue go back to a long-standing dialogue with my Japanese colleague Makoto Nakada (Tsukuba University) that started fifteen years ago.  One key difference between Japanese and Western conceptions of the self concerns the concept of "denial of the self " (Musi) in the Buddhist tradition. The individual self is not only nothing substantial but it is associated with selfishness. Being the ground of suffering it should not be protected but eventually annihilated reaching the nirvana. In the Christian tradition, the self is an immortal soul. In the Kantian as well as in the secular humanistic tradition humans represent humanity in their individuality having "dignity" and not a "value." According to Thai philosopher Soraj Hongladarom, although "from the ultimate perspective of a Buddha, privacy makes no sense whatsoever" it does make sense to cultivate compassion with regard to all living beings.  This key difference concerning the status of the self although it impacts privacy with regard to its philosophical foundation does not necessarily hinder a common perspective about its legal protection.
Western secularized and naturalized societies are still rooted in a two-fold perspective, namely the world of sensory experience and the world of sensible experience, or the physical and the meta-physical, having impact on the protection of individual privacy as being essential for the conception of freedom, autonomy and a free society. Japanese dwell also in a two-fold world, namely the world of traditional morality (Seken) and the morality imported from the Western world (Shakai). But on a deeper level, Japanese dwell also in a world they call Ikai which is "the aspect of the world from which evils, disasters, crimes, and impurity" arise.  This means that the concept of privacy has different meanings according to the perspective from which, for instance, a homicide is being reported. Beyond this three-fold view on privacy, Japanese make also a difference between 'public' (Ohyake) and 'private' (Watakusi). Ohyake referred to "the imperial court, the government, the nation, society, as well as to making things open and to being impartial" and today to the "governmental", while Watakusi means "partial, secret, and selfish."  The word 'privacy' in the form of puraibashii is a loan word in Japanese. According to Nakada and Tamura, there are two 'axes' that define public/private issues in Japan, namely the puraibashii axis and the Ohyake / Watakusi axis, both being intermixed. All this has impact in the way Japanese people view their privacy on the Internet no less than in the way(s) the press reports (or not) on 'private' issues and on the legal framework as well. Western conceptions of the self and of privacy open different ways of conceptual and practical dialogue with the Japanese ones.
R. Capurro: Privacy. An
intercultural perspective. In: Ethics and Information Technology, March
7, 37-47. https://link.springer.com/article/10.1007/s10676-005-4407-4.
overview see my "Intercultural aspects of digitally mediated whoness,
privacy and freedom" dealing with the Far East (Japan,
China), Latin America and Africa.
In: Rafael Capurro, Michael Eldred, Daniel Nagel: Digital Whoness.
Privacy and Freedom in the Cyberworld. Berlin: De Gruyter 2013,
How have discussions of intercultural ideas of ethics in the digital sphere changed over time - is it fair to say that there is a greater understanding across the board of these challenges?
UNESCO has been dealing with international and intercultural aspects of information technology since twenty five years.  The academic problematization of intercultural issues of information ethics or IIE (Intercultural Information Ethics) goes back to an international conference organized by the International Center of Information Ethics (ICIE) that was held at the Center for Art and Media in Karlsruhe (Germany) in 2004.  The International Review of Information Ethics (IRIE), the journal of the ICIE created in 2004 was devoted from its very beginning to an intercultural dialogue in the field.  Both, ICIE and IRIE, created by myself in 1999 and 2004, moved in 2020 from Germany to the University of Alberta (Canada) being now under the leadership of the Canadian Information Scientist Jared Bielby. Mr Bielby and the Australian Information Scientist Matthew Kelly edited the book Information Cultures in the Digital Age. A Festschrift in Honor of Rafael Capurro (Wiesbaden: Springer 2016) with several contributions dealing with IIE.
Since the Karlsruhe conference the field has grown very quickly with a lot of publications and symposia. The proceedings of the Karlsruhe symposium were published in 2007.  The discussions on IIE have diversified not only with regard to different issues and fields of application, such as roboethics or ethics of algorithms,  but also concerning the growing interest in different parts of the world such as Africa, Latin America and India on these issues.  The ICIE has organized several international meetings particularly in (South-)Africa under the patronage of UNESCO starting in 2007 with the first Pan-African Conference on Information Ethics co-organized by the University of Pretoria, the University of Wisconsin-Milwaukee (USA) and the ICIE, held in Pretoria 5-7 February 2007.  A special highlight was the creation of the African Centre of Excellence for Information Ethics (ACEIE) at the University of Pretoria in 2012 under the leadership of Dr. Coetzee Bester organizing regularly pan-african symposia in different African countries as well as workshops and seminars, including online publications.  IBICT (Instituto Brasileiro de Informação em Ciência e Tecnologia), which is linked to the Brazilian Ministry of Science, Technology and Innovation, has been active for more than twenty years promoting information ethics in Brazil.  The Latin America & The Caribbean Chapter of the ICIE is headed by Marco Schneider, Arthur Bezerra and Cordel Green, researchers at IBICT as well as in several Brazilian universities. Schneider directs the research group Perfil-i (Perspectivas Filosóficas em Informação) out of IBICT in partnership with Rafael Capurro and Arthur Bezerra. Bezerra directs the research group Escritos (Estudos Críticos em Informação, Tecnologia e Organização Social), with the participation of Schneider.
The International Society for Ethics
and IT (INSEIT) organizes together with the International
Association for Computing and Philosophy
(IACAP) the CEPE (Computer Ethics Philosophical Enquiry) conferences
2000,  the next one on "The
Philosophy and Ethics of Artificial Intelligence" 5-9 July 2021 in
cooperation with the University of Hamburg. 
Charles Ess has organized
conferences on "Cultural Attitudes towards Technology and
Communication" (CATaC) since 1998. 
Coming back to your question: How have discussions of intercultural ideas of ethics in the digital sphere changed over time - is it fair to say that there is a greater understanding across the board of these challenges? Yes, the discussions on IIE have changed over time and the plethora of meetings, publications and creation of centres all over the world provide enough evidence that there is a greater understanding not only within the academia but also having large impact on society at large through the mediation of social media and particularly through a growing number of zoom meetings open to a larger audience.
International Policy Dialogue on IFAP Priority Areas in the
Countries organized by the African Centre of Excellence for Information
(ACEIE) held in Cape Town, South Africa, July 4-8, 2018 as well as
International Conference on Access to Information in Time of
Crisis - The
UNESCO Information For All Programme Priorities and The
Pandemic, 26-28 August, 2020 organized by India Centre of
Information Ethics (ICEIE), Centre for Digital Learning, Training
Resources (CDLTR), University of Hyderabad (India); African Centre of
Excellence for Information Ethics (ACEIE), University of Pretoria
Africa); Russian National IFAP Committee, Interregional Library
Centre (Russian Federation); UNESCO Chair on Language Policies for
Multilingualism, University of Santa Catarina (Brazil). My contribution
debate: On biological and informational pandemias. http://www.capurro.de/pandemias_engl.html
International ICIE Symposium 2004:
Localizing the Internet. Ethical Issues
in Intercultural Perspective, 4-6 October, 2004: http://www.capurro.de/ICIE2004Symposium.html.
Rafael Capurro, Johannes
Frühbauer, Thomas Hausmanninger (Eds.): Localizing the
Aspects in Intercultural Perspective. Munich: Fink 2007. See also the
comprehensive book by Soraj Hongladarom and Charles Ess (eds.):
Technology Ethics. Cultural Perspectives. Hershey, London, Melbourne,
Idea Group Reference 2007.
 See R.
Capurro: Intercultural Roboethics for a Robot Age. In: Makoto
Rafael Capurro and Koetsu Sato (Eds.): Critical Review of Information
and Roboethics in East and West. Master's and Doctoral Program in
and Advanced Japanese Studies, Research Group for "Ethics and
in the Information Era", University of Tsukuba 2017 (ISSN 2432-5414),
13-18; R. Capurro: Enculturating Algorithms. In: Nanoethics (2019)
The proceedings were
published in the International Review of Information Ethics (IRIE):
ACEIE is now part of the ICIE as its African Chapter: https://www.i-c-i-e.org/chapters.
 http://www.it.murdoch.edu.au/catac/ See also: Charles Ess: Lost in translation? Intercultural dialogue on privacy and information Ethics. In: Ethics and Information Technology, 7 (2005), 1-6.
How difficult is it to reconcile
Western centric platform design with a multitude of different ideas
Societies, having different moral and legal traditions, approach the issue of privacy from specific perspectives and needs as the example of Japan shows. At the same time the growing academic dialogue on IIE makes possible if not to 'reconcile' at least to open paths of thought that make possible to cross over from one culture to the other, cultures themselves being a dynamic result of several forms of hybridizations over centuries. Even if there might be issues, like the example of the self shows, that remain basically different, this does not mean that the frameworks upon which they are based are incommensurable to one another. The task of translation is a core issue of IIE and makes possible to understand each other by making differences explicit. The 'reconciliation' at the theoretical level does not aim at producing some kind of 'Western centric platform' with different ideas about privacy converging integrated into it, which would be a kind of Western cultural colonialism. Even the creation of different kinds of international declarations such as the UDHR and many others also in the information ethics field, such as the Tshwane Declaration on Information Ethics in Africa from 2007  and the Hyderabad Declaration from 2021,  are examples of unity in diversity particularly concerning practical goals under the umbrella of basic principles and values but without necessarily a deeper understanding of such principles and values from a philosophical perspective. In other words, 'reconciliation' is a concept with different meanings according to the context in which it is used. Moral and legal systems can be understood as a kind of symbolic immune systems that protect a society from dangers coming from outside the system. But if immune systems, as in the case of biological ones, are not able to evolve naturally or artificially (such as with a vaccine) they turn into a death cage. In other words, morality needs a critical reflection which is called ethics in order to evolve. Ethics is, like any other scientific field, a never ending process. It is important not to confuse the object of reflection with reflection itself. 
 Tshwane Declaration.
 See: John Ladd (1985). The Quest for a Code of Professional Ethics: An Intellectual and Moral Confusion. In: D.G. Johnson, J.W. Snapper (Eds.): Ethical Issues in the Use of Computers. Belmont, CA, 8-13.
Is it possible to move from a dialogue to a merging of differing visions of privacy?
I think that what the development of the last twenty years shows is not some kind of unified vision of privacy neither at the theoretical nor at the practical level, but a growing concern for respecting different concepts and traditions of privacy while being aware that at the practical level there should be a consensus on the way(s) how to deal internationally with issues of cyber crime and cyber security that concern not only society at large but also the personal lives of individuals locally and globally. I think that we need some kind of international agreement as in the case of the United Nations Convention of the Law of the Sea or the Convention on the International Civil Aviation that does not need to be based on a merging of different visions of privacy, but on a consensus that whatever the basic cultural differences concerning privacy and publicness might be, all partners have a common interest in the protection of the safety and security of the citizens as well as on formal mechanisms for dealing with controversial issues. Even this minimum on moral consensus might sound utopian in a world in which wars between states and criminal deeds of all kinds in the internet or by using it as a medium has become an unwritten norm of action with growing bad consequences at all levels of society. Declarations are a first step but they need some kind of legal status as well as the provision that actions against the principles stated and agreed upon will be prosecuted.
What are the risks around digital
balkanisation when it comes to national regulation driven by
different approaches to core concepts such as privacy?
This vision is not only the opposite of digital balkanization but also the opposite of some kind of regulation driven by the power of a state or group of states as well as by IT dinosaurs for whom human communication is a potential endless source for capital building beyond the needs of the people and particularly of those that cannot express such needs because they have no digital voice to do it. Such dinosaurs disguise their ambitions with ethics committees within their companies or financing ethics institutes (more and more on AI and Ethics) in public universities. With quasi-religious proclamations about their goal 'to make the planet a better place' they are in fact a powerful incentive for balkanisation which turns into a form of resilience that hinder their will to power.