Mangrove didn’t work for me. No knocks against it. It does cool stuff; it just feels like a module for someone else. Another option would be crow + W/'s new synthesis mode, but you’d also need to add a TXi or something for controls, so it becomes quite expensive quite quickly. You’d be in very “roll your own” territory, but you also get to have a lot of say in how things sound and what you can change.
There are some things I haven’t tried: Bassline, Domino, M303, the other NE stuff with envelopes.
There’s also the semi-modular route, which gives you a full voice, but obviously isn’t going to be compact: Atlantis, Manther Growl, Tonestar 2600, SV-1, Lil’ Erebus, Moog’s stuff, etc.
Once you leave self-contained, then you’re just back to “which oscilators do I like the sounds of”. I think Plaits is good for exploring that. It offers some of everything. At the very least it can provide more direction for you.