Hey. I need some feedback. The application for this synth is for learning synths, sound and signals.

I suggest adding DATA by Mordax and mixer(s).

looks solid, maybe add some more mixer/vca for all those voices to be able to modulate/mix them better.
also, passive mults waste hp in my opinion, just get stackcables or "fly" your passive mults between the cables =)

More modulation sources for sure. The quad ADSR is great, but you've got a lot of audio sources that will greatly benefit from modulation. Also, you've got a lot of clock/logic signals, but I'm not seeing many modules that benefit from clocks. A sequencer, turing machine, clocked random source, or clocked LFOs would take great advantage of all those clocks.