SoundFont Format Extensions Specfication

After 2 years and a computer failure, I and some other people have managed to put our 2023 attempt at extending the SoundFont specification into an actual and proper specification, called SFe, available here:

https://github.com/SFe-Team-was-taken/SFe/releases/tag/4.0

We have Polyphone's developer, as well as other player developers, in on this.

We have also resurrected Silicon SoundFonts (Section 11 of the SoundFont spec, which is an official SF2-to-ROMpler mode, and I've documented it with a reference implementation here: https://github.com/stgiga/siliconsfe/tree/main and it's factored in to our new spec.)

I've talked about this with Fluidsynth, and hope it gets added to MuseScore as someone who has used it for over a decade.