Camera movements very choppy since BH patch

Thank you so much for responding and helping, puzzleaddict, I appreciate it so much!! ❤️

I did following tests:

Setup: I tested while having loaded into an area in live mode, it is day time (when it's the worst), and waited until the neighbourhood had spawned some Sims walk-bys. I am loaded into a Sim that has a small business (allowing parents to stay with their kids/tods/infants), and opened the business, as that creates the maximum camera choppiness, so I can best compare the different states (but it also happens when I just play a household without a business, especially bad in community lots). I'm also running "fps on" as it confirms the visual choppiness with a frame rate drop by approx 50-70 fps (goes down to 35-70 when chopping). For testing I 1. use right click panning over the town, and 2. have my Sim drive around with a bicycle and am following her sidewards (by right clicking on her profile image and positioning the cam sidewards of her, as it makes the camera jumping clearest to observe). I play on speed 1 nearly all the time and walls up if that matters, highest graphics options and Vertical Sync on (I tried it with Vertical Sync off too, but didn't see a difference).

1. Right-click to pan the camera: I already am using right-click to pan the camera (Sims 3 cam), I don't have edge scrolling on, so I assume I'm unfortunately already using the most performant one by default. I also use the keyboard WASD to move the camera, sometimes in combination with "holding" the screen with the mouse middle button to rotate and move, but both have the same stuttering effect.
2. Eco footprint disabled: My Game Option "Enable Eco Footprint Gameplay" as well as "Eable NPC Voting" are both always off already. I also have "Build mode items grant gameplay effects" always off. But I strangely still experience a popup sometimes very rarely that tells me that the footprint changed, which is probably a game bug. Because of this bug I do have ALL of my buildings in my whole save have the lot trait "Eco lot", as a way to prevent that the bug moves my worlds into industrial phase and ruins the beautiful atmosphere. Not sure if there is a way to actually fully disable footprint more than what I already have disabled? I definitely don't see the eco footprint UI anywhere in my game, and usually don't have any of the aurora etc effects.
3. Fullscreen: I usually play on "windowed fullscreen" -> I now tested on "Fullscreen" with my native 2560x1440 resolution, but it made no difference, same frame drops and choppiness when panning or following my Sim. I also tested on "Windowed" and it was either even worse or the same (had a drop to 30 fps at some points, but I also observed them in full screen at some rare times). All 3 modes were choppy, compared to what I had experienced in my game all years so far until the BH patch.
4. DirectX 9 / 11: I usually play on DX11. When switching to DirectX9, restarting, and playing at that same point again (with still open business), I still have the same choppiness and frame drop when panning. I feel like the performance with DX9 is even lower, the frame drop went down to 25-35 (10 below DX11) and the general fps while standing still and paused was only at 70-90 (compared to 120-140 with DX11 in the exact same location / perspective)
5. Willow Creek / NewCrest: I tested in my current and a fresh new save:
   In my current save I experience the same choppiness especially in bigger neighbourhoods like the one in willow creek that has the nightclub (Crawdad Quarter), and also in other worlds where i tested in Brindelton Bay at the coast on the biggest lot, or Ravenwood, right neighbourhood on the 30x30 at the water close to the rock head, especially when the festival in the evening starts. FPS goes down till 40-50 when it is choppy, especially when visiting a community lot.
   For a fresh new save file at the start it is completely fluent, the same way as all my main-save neighbourhoods are when I just load in at the start before Sims spawn. To reach choppy levels in a fresh save i had to play for a while and I added 4 random families (in all different ages, incl a horse, dog etc) to willow creek as there were barely any Sims out (and added clubs that can meet in community lots, to make it a bit more similar to my save, even if it is highly reduced). The choppiness is less heavy and long (goes down to 60 fps from normally being 140 fps), but is still happening when panning while playing in a community lot and approx 17 Sims are out and about.

Some additional observations (not sure if they matter) :

• Every time i load into a neighbourhood my game starts 100% fluently and on 140 fps without any choppiness at all. When I pause right at the start in the first second, and then pan around the neighbourhood for how ever long i want, it's fully smooth, no matter how complex my builds are. I can see the different LODS moving in and out without issues, textures loading etc, the frame rate goes down but it doesn't stutter the camera movements, on highest graphics settings. It only starts stuttering as soon as other Sims are spawned in, especially panning over them.
• The camera panning is also choppy when the game is paused in live mode, as long as there are Sims loaded in the streets.
• The camera is panning 100% fluent (choppiness at all) when in build mode (from managed worlds, on the same lot), but it is choppy when using build mode coming from live mode (as long as there are other Sims on the streets too)
• As everything hinted to issues with Sims, I tried to move all my graphic settings that are Sims-related fully down, and deleted localthumbcache: 
  - Sims = Low
  - Uncompressed Sim Textures = off
  - Edge smoothing = off (not sure if that is effecting Sims but i thought i'll try it)
  It still stutters but definitely less when I'm far away panning over the Sims in bird-eye distance, but when coming closer it is as bad as before. And of course it's not an enjoyable state not seeing the faces of my beloved characters, it shouldn't be suddenly necessary if a high level of detail was ok before BH patch..
• My observation of the choppiness coincided with the appearance of the new file localsimtexturecache - I have no idea if it has anything to do with it, just noticed that this got added at the same time as the issue began. Might be a coincidence, but I thought I'll mention it.
  I did try to delete the file (given it's a cache i assume it's safe to delete similar like deleting the thumbnailcache), but didn't notice a difference in performance. I tried observing the file reads/writes into this file while panning, and saw it being written to but not read, but not sure if it's meant to be read during live mode anyway. Happy to test anything if you have any ideas?
• The choppiness is similar to when you place a new build from the gallery on a lot, and try to move the camera before the name of the lot has updated to the new lot name (I assume this is the time the game needs to load all textures / geometry) -> this is a similar choppiness, although maybe half as bad, because it starts choppy, then becomes fluent, then goes back to choppy when i try to move again, and so on.
• My save file is a 4-year long rotational save that includes every DLC, with every single lot of all worlds lovingly placed from gallery (usually not-cluttered builds, as i like simplicity), with 42 played households (121 Sim Count) and regularly cleaned "other households". I have 19 clubs, and my Sims have lots of relationships, inventories that i clean from time to time, especially deleting photos i dont need, they have jobs, skills etc. => This will likely be heavier than a fresh save which could be why fresh saves perform a bit better, but what is strange is that all this had not changed when I updated to the BH patch, and suddenly it was choppy, while it wasn't just before that.. I even tested with the BH world freshly in my main save, without building anything in there, it was starting out choppy right away after the update (another reason why i assume it doesn't have to do with buildings).
  
  

This is all I know so far and have done testing on. I hope it might spark some idea what the issue could be?

Thank you so much again for helping ❤️