Already reported and posted some of these, but I'll repeat them here - and I'm pretty sure that most of these are patch 4-related, since I'd never run into any of them prior to patch 4:
- rubber-banding/lag when running and/or fast-traveling between named locations on the map in Act III. This has gotten better for me with hotfix 11, but it's still present in some locations of the Act III map (albeit much milder than before hotfix 11).
- trying to switch off DLAA in the video-options makes the game CTD instantly. Only tested this on Vulkan but it has been 100% repeatable for me since patch 4 dropped.
- not 100% sure if this is a patch 4-thing: Character-portrait messed up when leveling Minsc for the first time after he joined the party. Parts of his inventory portrait got superimposed over his UI-portrait somehow and that's what it still looks like now.
- SH romance dialogue options available that should not be available given the state the romance is in - basically, all options for different and mutually exclusive relationship-states are available at the same time. Also had her "reset" last night to the state she should be in the morning after the swimming scene. Meaning I could talk to her about building sand-castles twice and on two different days.
- some dialogue-scenes cutting back to normal world view prematurely (before the last character speaking during the "cut-scene" is able to finish their sentence).
- Potent Robe model's skin/texture glitching out and showing weird black and white pattern beyond a certain viewing distance - but only on some body-types. Definitely happens on small-bodied males, doesn't happen on Karlach for example. Same behavior for the actual "Potent Robe" and Larroakan's robe (which shares the same model).
EDIT:
- some general weirdness with dialogue sequences. Happened to me twice after patch 4 so far:
1. Wyll at camp - trying to talk to him switched the camera to external, "someone else is having a conversation"-mode while the Emperor appeared standing around at camp (this was in Act II, before it was even revealed the Emperor existed, lol).
2. Gale and Mystra at the Tabernacle. Happened a day after their dialogue-sequence when I returned there and - with Gale active - clicked on the statue. The game moved the statue off its pedestal and next to Gale, facing him as if it was an NPC having a chat with Gale.
In both cases, SPACE/RMB to skip would eventually fix this behavior (Wyll conversation starting normally, Mystra statue returned to it pedestal).
EDIT2:
Probably not a patch4-thing, because it never worked correctly for me, but I'll throw it in here as well:
Oskar's painting will show anyone but Tav when dropped on the ground. So far, it's been Karlach and Minsc mostly, I think, on my play-throughs. Sometimes the portrait will even change during one and the same play-through. It's never shown Tav's portrait, however.
At least it's now worth quite a bit more - I usually robbed the whole place blind to make this mission a bit more ..err... rewarding.

S.