Quad Mono block is easy, though you will get the same thing if you just hook up every second input and leave the other side unconnected. Probably easier for me to do the octal version to be honest, with 8 mono ins and outs. Less VSIG to change.
I’ll try to have a look at it over the next couple of weeks. It will make a nice change from the insane complexity of the 4 voice synth