I see. I still feel this must be carefully thought out, because although exercises are being discussed online, this platform could potentially outright distribute them all at once in a centralised manner. And it can be a source of tension, specially without attribution (I've grown a bit more sensitive to this issue after realising how much effort goes into producing good exercises, like Advent of Code for programmers).

I think there would be value in knowing a given exercise comes from chapter X of book Y; it might even help track knowledge dependencies, so to say (to solve exercise Z, student probably needs exposure to all chapters between X-3 and X). And it could also be possible to build thorough different levels of exercises in different areas: a set of basic computation exercises (invert this matrix; solve this simple integral) - and these exercises, as you probably know, can be generated easily; some intermediate exercises of theorem applications; and then groups of higher difficulty material (which are probably somewhat more creative exercises).

Anyway, this is really an inspiring project and I hope it brings you lots of joy! and, in case it helps anyone, I've found a good trove of mathematics resources over at https://math.libretexts.org/Bookshelves.