For the question "where can I get free feedback for the exact obscure thing I'm doing": probably nowhere. But if you're searching for:
Composers who use mathematical / algorithmic approaches in their
like the subject line says, then I'd look at electronic music genres, not classical.
I won't try to list forums and social networks where these people hang around, but I guess you'll find links. If your generative music is interesting, electronic music makers might resonate with it. Could you for example make your Python scripts dispatch MIDI events in realtime, so it could be used as source material for a modular synth?
Instead of trying to find an audience for the exact (relatively obscure!) thing you're doing, you could try to find an audience or community that's at least close to what you're doing, and try to adapt your software to that environment.
Musical notation doesn't feel like the best delivery format for generative music. If you have a generator that's capable of producing thousands of hours of music, why print it out. Those who are able to comment on music, usually want to hear it. Having it in notation doesn't add anything. But if you want your compositions to be treated as if you had hand-written them, then the fact that a computer was used for facilitating some aspects of the writing process is not really relevant, and you're just in the same line with millions of aspiring composers out there.