ok so! little refresh: polyproto is the WIP federation protocol that aims to be simple and build on existing, robust tech and protocols instead of re-inventing the wheel, while avoiding complexity from i.e state-resolution or extension fragmentation.
Polyproto is also on fedi at @polyproto, and is part of the @polyphonychat project which eventually aims to use this protocol to build a chat platform.
we encourage in the spec that extensions should never duplicate functionality found in an existing extension (especially the official ones); we also note in the spec how implementations should always prefer "vetted" extensions, i.e those that were signed-off on by us. Additionally we encourage spec extensions to not be one-off small features, but instead to have extensions covering a specific usecase (i.e chatting), and then that has smaller extensions.
None of these methods are fool-proof, but it doesn't hurt to try things out.