Hi Chris,
I really would like to help, but so far I can’t do more.
As usual, I have so far only an image from your scene. Images might give a tiny glimpse of the scene, but that is all there is to it.
I rely on scene-files, pretty much always. Anything else is not really how I can give you any further advice.
What I know so far, is, that you have a small scale, but you like to have also a larger scale in the scene. Which eliminates to a certain degree the comfort to set it up with the Project settings in general.
On the other hand, I really don’t know if your set up causes the trouble, independent from the scale. Who knows without scene-file.
So, to get at least a little bit into the helping position I made a very tiny scene and set the Project settings to the opposite. Even then it worked. In other words, set the scale and check if the problem vanishes. If not, its probably not the scale.
Caching or even writing parts out as Alembic, might help.
Let me know when you have something to share, even privately. A scene reduced to the parts in question, with no 3rd party items in it, please.
Cheers