@ Ragnarok
I'm not sure outright nerfing the encounters (or creating more risk, if you will) is really making things more tactical. It seems to me that it just makes it more likely that you'll avoid the hassle and grind it out on a stable footing, wait for the AI to take a "tactical" risk, and then blast the rafters or what have you. And I'm not sure that really would be an improvement. There's not a whole lot of tactics in trying to weather the storm and winning by attrition unless the AI does something silly that lets you speed things up. It's more passive and defensive, and having to rely on that all the time would probably be less satisfying than what we currently have. At least for some people.
In terms of shoving, I think it gets nerfed too far if enemies just go prone on position, as it would leave your position infiltrated. Your ranged characters probably need to move away to gain distance for shooting or use much weaker melee attacks. Essentially, you've lost control over the space and taking it back will mean a straight up fight, which is probably a tactical advantage for the AI. If we could do serious area denial effects to cordon off areas and maintain positional control that way then it would matter less. If tanks could focus aggro then it would matter less. But neither is possible at the moment. Generally speaking, what we have is a mild AI dislike of messy surfaces and the ability to shove enemies around a bit.
Rather than taking out our ability to move enemies (and their ability to move us), I'd rather see the AI starting to take cover, break direct LOS to make it harder to attack them from distance, and maybe even worry a little bit about ledges. Right now the AI will happily action surge double dash just to stand out in the open, right near a ledge. Next turn, misty step way up high and stand right near a ledge. It's like they're almost begging for a little nudge and it just wouldn't feel right to deny them.
In my admittedly limited experience, I am finding it very useful fairly regularly to hide most of the party and just have one character start a fight, giving me control over enemy aggro and largely directing their movement. They can't kill Mr Squishy when he's not in the fight, and then he'll have all the time in the world to join the fight at just the right time. I do not think this is entirely as it should be, but it is fairly reliable in keeping the party safe.