I’ll definitely look deeper into Maths, but I always disliked the almost illegible font - i guess that’s probably why I’ve steered away from it for so long. I hope I can find a Grayscale version/faceplate of it. Are there any other versions of Maths you recommend (if any)?

-- Avesta

I feel you...the Make Noise "edgy" look is kind of annoying. I prefer modules that clearly show what's being done instead of rockin' some graphics that only wind up confusing/annoying the user. This is why I don't think much about effects pedals that have overdone, elaborate graphics (see here for an example: https://reverb.com/item/53789313-digitech-dirty-robot) that makes it more difficult to see knob positions, etc due to all of the busy artwork on the case. So, yeah...get the Grayscale panel.

Now, as for Maths-ish devices, there's the direct predecessor of that, the Serge Dual Universal Slope Gen. Several years ago, I would've told you that if you wanted one in Eurorack, you'd be screwed. But these days, Random*Source over in...Sweden, I think?...has many of the Serge circuits adapted to Eurorack. So here's their version of the DUSG: https://www.modulargrid.net/e/random-source-serge-dual-universal-slope-generator-dusg-mk2 With these, you don't need an entire Serge panel or half-panel...you can get JUST the module, which is also rather un-Serge-like. No, not cheap...but still far cheaper than if you had to buy one in the "old manner".

As for the Tangle Quartet...there's a workaround for that if you want to use them for audio, and that would be an exponential envelope gen. And it does appear that the Zadar is capable of generating those, so not only would this be a decent EG for the rig, it would "correct" the VCAs so that they behave exponentially even with them being linear VCAs. DEFINITELY get the Nin expander, though...it's got some assignable CV ins and a four button direct selector for the envelope generator in only 3 hp.