I have a high poly object being translated by an animated parent Xform. This is signalling to Houdini that the item is time-dependent, and so Houdini keeps re-importing the SOP geo on every frame. Is there a way to avoid this? Or do I need to just do a separate SOP import + parent object and parent the geometry with nodes in LOPs?

https://www.youtube.com/watch?v=s12xnzPaU44&t=151s [www.youtube.com]

You can cache and probably saving it to a USD file won’t hut.
I can`t get it to properly work with crowds though.

Right, so I can't achieve better performance just via the Scene Import LOP. Will see if caching helps, thanks.