One module I suggest on occasion as a "Maths substitute" is Doepfer's A-171-2, provided you install a pair of them. This doesn't work in many skiff cabs, though, as the 171-2 is 60mm deep. However, it does save a whopping 4 hp. Or a not whopping 4 hp...depends on how you look at it.
On the other hand, we could just all accept that Tony nailed the design of this thing with the current revision and plan for a 20 hp hole that has to be there for it. It's 100% one of those things where the designer makes something so ideal that it would be difficult to totally replace it, like Moog's transistor ladder VCF design.