Stages is nice, but you get a maximum of two ADR envelopes. I just got a Zadar and it is a really neat one, albeit I’d still give a slight edge to the Malekko Heavy Industry Quad Envelope as there is no menu diving at all. There isn’t much in the Zadar either and the are rather similar in functionality, so both would be great.
Regarding the mutable instruments modules: many of them are available as micro versions that can save tremendously in HP.
Michigan Synth Works makes some nice ones, such as an 8HP version of Plaits, Forms. Antumbra makes beautiful DIY kits, such as Cara (a 10 HP version of Marbles). They are offered fully built on eBay. Mistergoop does some really fine work.
Here are a uO_C from Michigan Synth left and the Cara in action:
https://i.postimg.cc/5tCyrwyp/15-CAD18-F-9-F0-B-4-E01-A635-2-B8252-C5-C2-DC.jpg
These micro versions are great space savers, albeit the ergonomics of some of them may not work well in a performance setting where you plan to constantly tweak such a module. Especially the use of trim pots can make them less well suited for that task. I don’t see it as much of an issue for Plaits or Forms.