Well done @dachary! Concise and comprehensive.
Though I still find it a missed opportunity in how you position FedeProxy as the “sub-optimal, temporary band-aid solution” until full native support in forge software is achieved. On the contrary FedeProxy has the opportunity to be forever more powerful than native forge-2-forge support, when it sits as an independent service in the middle between forges. Positioning it so needs not be a lot of extra work, other than ensuring future use cases can be facilitated and don’t need an overhaul, or are impossible altogether.
The “sub-optimal” case then constitutes your MVP, while the project itself is more visionary and exciting to potential contributors. You don’t ever need to go there, but will keep the path open.
(Related to earlier discussion on issue federation development plan)