Thanks @danielwinterw,
This helped us to get a better understanding of some aspects of this indeed multi-faceted and thus rather complex issue.
We have just filed a separate issue for one aspect that now turned out to be unrelated and only amplifying the impact during the incident:
We are unable to reproduce the main issue (consent grant flow does not finish in Confluence) with a privately distributed app, so it might indeed be related to the specifics of a cross-product Marketplace app, and we obviously don’t want to mess with our production deployment to debug this.
As a result, we are kinda blocked on reinstating your team’s cross-product app deployment advice as a workaround, so getting more insights and guidance by @rfernandes would be very much appreciated 