great system btw!
Metron and Metropolix both have probability, pams has euclidean, zadar has bursts, cara has controlled loopable random (botb cv and gate), batumi can self modulate. think up some processes that excite you! Use mixers, mults and attenuation you already have to glue your modulation together! matrix mixer is a great idea if you must buy something. but looks complete already to me!
monorail tech talk is a great youtube resource to think better with ingredients.

if the size of your system creates overwhelm, throw 5-6 modules in a smaller case to focus on how to wring them out.