Solasta baffles me since it's combat-driven, custom party and turn-based, and I dislike/hate those in cRPGs. And yet I find myself drawn to Solasta, I've already bought it, support pack included. Holding off until I play IWD so I can compare them.
All of this is exactly me as well. In my case I mentioned to the TA devs during their KS campaign (which I modestly backed) I'm doing so despite the many reasons I have to dislike their game (the three you mention being at the top of my list as well) because I want to support a new studio making cRPGs in the hope that their future games will be more to my liking. So supporting Solasta is a one-time thing for me.
I just saw you on their forums.

I really hope they succeed. Even if I end up not liking the game very much (for the above reasons), I think they can offer a lot to the genre, if other devs decide to incorporate those good things into their games. *coughLariancough*
Off the top of my head...
The map. It's amazing. This is exactly what I wanted to suggest for BG3 a long time ago. It would work very well with the focus on verticality. And it looks so nice!
The party and personality system. Ok, I'm not a fan of custom parties and no set companions. But I really like this system of the party coming alive through personality flags. As far as I can tell it's quite crude and limited in Solasta, but I hope this evolves, be it in the next TA game or some other RPG. I'd love a similar system implemented in BG3 for non-protagonist custom party members (artificial companions with personality). Unlikely of course, but hey, one can dream. (As I'm more and more seriously considering a custom party...)