get a quad cascading vca - such as veils or intellijel - either will be able to be 4 vcas, 4 external input amplifiers, a 2-4 channel voltage controlled mixer

Maths is a great module - but it is more than the sum of its parts - google the unofficial "maths illustrated manual"

kinks is another great module that will add a lot of functionality in a small space = including logic!
-- JimHowell1970

Thank you @JimHowell1970 just followed you on instagram

With your suggestions, updated rack looks like this. Appreciate the direction from both @Lugia and you
ModularGrid Rack