Nice initiative! Yes, this sort of work is very much needed for more and better Mac OS 9.2.2 development!
I myself wanted to do this way back in 2021, until things... happened. And life priorities shifted. But I always wanted to see an initiative like yours become reality.
It may not be fully fleshed out yet, but what you got is already incredibly helpful, and it is good enough to encourage others to get started on developing their own Mac OS 9 apps.
Currently I'm working on a REALbasic DR1r33 project (with help of later versions to target certain additional platforms), but after that I have plans for another project, and that will likely be in pure ANSI C89 / ISO C90 (while still conforming with K&R C), using probably Fantasm 6 and the final version of Apple's MrC compiler. Once that is ongoing, your page will be of great help, and I will gladly submit a merge (AKA pull) request to your Git repo if I think I can flesh out any of the sections there.