Thanks for the tips !
I've been looking at the Mantis also, it's true that I had in mind to quickly change to a bigger case after filling this one, you're right that's it may be a better idea to get a two row one now.
I just learned hours ago that the Bialismus is a VCO not an effect centered module - I had heard several times before that it had great effects I just assumed it was mixing not generating - so you're right that it's too much sources for a start. I'll go with the Plaits, probably, even though the Iteritas one looked fun. The Plonk one is just added while messing with my config, it's a module I'll probably buy much later if it stills interests me.
I was heavily leaning on an additional mixer already so that's confirmed.
As for Maths, I looked into the docs yesterday and it ticked several boxes for me. Just checked the link you shared, I will look heavily into it, seems like great infos on the module and on modular in general.
Didn't know about the Mutant Brain, looks like a great alternative !
Would you recommend trying my luck at a DIY case ? I've been thinking about it, could save me a few bucks.
Thanks again!