I can name that flaw in two words: "envelope generators". Maths can do that, but using Maths as an EG is sort of like having a Bugatti Veyron...but only using it to go thru the McDonalds drive-thru. Same goes for the Stages. These are 100% part of the basics of synthesis, and you can't really get the best results out of this without several EGs. So, I'd suggest filling 18 of those 20 hp with a Quadrax and its Qx expander. This gives you four two/three stage EGs which can also be looped as LFOs, plus the Qx allows a lot of triggers you don't normally find on the panel to be used...and not just with the Quadrax, but those "End of..." pulses can fire plenty of other events.

Plus, Maths + Quadrax/Qx = MAD modulation capabilities when tandemmed.