Thanks Phil and team for the detailed doc,
We'll discuss this as a team, so these are my personal reactions:
1) Are there any examples of data repositories that work as SPAs? How well does this interact with PID services, standard user expectations for stable URLs for content, etc?
2) I'm more worried about accessibility of SPA than the document. Sure, there are React.js guidelines/tools for accessibility, but SPA's do pose specific accessibility issues, much current accessibility technology is designed with standard websites in mind, and many of the WCAG standards are also most clearly described for standard websites. That means that, as I understand the status quo, writing an accessible SPA requires specific accessibility design experience/knowledge. Given more stringent EU regulation entering into force, and more stringent US enforcement of existing regulations (and, of course, the fact that accessibility is a human right), this can't be a secondary consideration.