Well, there is potential, but maybe not for OB. I don’t see what making it open would add to it really.
The korg SDK is a nice start indeed. Opening FX programming when they’re digital anyway makes a lot of sense for most case, and honestly I’ve been looking for something like this for quite some time.
A counterexample to this would be the Novation peak. They use an FGPA for the oscilator and FX. I don’t know much about FGPA programming except that it’s hard to learn, and there’s not many people out there who know how to program an FGPA so new custom FXs would take forever to come anyway.
Eurorack is particular, for most case I don’t think the schematics are that complicated, and some uses chips for the audio processing anyway, so it’s still mostly a progamming job. I agree that manufacturing is a whole other problem in itself though and doesn’t simplify things.