Ambitious Yes, expect to achieve highly unlikely but who cares, I am giving myself alot of time to chip away at it, not too fused if I don't get their, but it will be cool to learn about it along the way.
Yes, vactorals are controlled with PWM.
For outputs, what I see is, you have your base signal per per pedal, split the signal into two with a buffer splitter, control both levels with Vactrols, one signal goes to the pedal, the other signal bypasses the pedal, and then both signals are mixed back togethether befor the next pedal.
Matrix side.. (not like to matrix's I have seen on line)
For each chanel of the matrix mixer, there is cascading buffer splitter,in the case of 5 pedals, 5 buffers, first split to 5 out puts, next 4 and so on. I have found with this setup, pedals can be sequenced in series and or parallel as prefered, but unlike the matrix mixers I have seen on line, you can't feedback onto a pedal already being used in an earlier sequence. Vactrols will be at each buffer output to be able to select the desiredpedal sequence.
The reason for all this is because I think current pedal loopers are severely overpriced and very limited with what they can do, and in additionj with this setup, adding the vactrols allows it to be controlled by midi. And I have also seen realy awkward attempts to retro fit midi systems to guitar pedals, and convinced there has to be an easier way. On paper, the idea is cool, and happy to share as may be someone esle may get enspired and be better at doing it.