I use MBK choc for vertical combos, it is stable and reliable. I like it.

Just a short term thing. You asked your fingers to think twice before typing. They are giving you opportunity to rewire muscle memory. Once you are done learning they will go back to normal.

Shameless plug, try Flactyl it has plenty thumb cluster keys, and heavy tenting out of the box. You can also customise your angle via OpenSCAD. And I will be happy to help you build it if you need, just drop me an email (you can see it on the repo)

I feel like I want to contribute more to bootstrap this community :)

I use it for shift, and I like it so much more, because pinky would be overworked otherwise. However I use Flactyl and it has a ton of thumb keys, so your milage may vary if you do not have enough keys.

BTRFLD check this out. Does is count?