Just do it like in Solasta... you can either shove prone or shove 5 feet away, as an action, or part of attacks. Like in PHB. Done.
"Just do like in Solasta" solves pretty much every problem with BG3's combat.
BG3 EA combat is way more varied and interesting than Solasta’s IMO. I understand some complaints about 5e implementation, but Solasta’s enemy behavior is incredibly dull. Being sometimes frustrated by a shove KO is still better than having enemies that just attack the closest for 90% of the time.
While I mostly agree with this, it's still really annoying to be one shot. I didn't really understood this complaint until my patch 8 playthrough in which I got shoved a lot lol.
Being OS like this may not happen so often. The consequence for a "not so good" position may lead to a game over and sometimes it can come just because of the map design (you cannot be far aways from holes).
I usually survived in my playthrough with 3 characters but it was hard and I've played the game for 500+ hours.
My frustration was high and d I guess a new player would be frustrated even more, or eventually totally discouraged.
I also dont fully agree with what you said a bit later.
Many classes don't use a bonus action at every turns so Larian's new BA became very common action.
I understand the idea behind this and I'm eventually ok with it. But shove is really powerfull in BG3 and I dont think it's a good thing to have such a powerfull "common action" available at every turn.
It may be fun when we're shoving but it's also often extremely frustrating when you're the target on top of being a very optimal move in combats. Having "over the top" options in combat is usually not very interresting in tactical games imo.