They really need to develop a visual proxy system for complex components that you can toggle on or of IMHO.
All these complicated workarounds are really a pain IMHO, they could use the pointcloud ability of Rhino, since these display really fast.
If they would then give the user the ability to display every N th point (N would be user defined, dependant of the wanted complexity/performance).
It could even be done as a viewport mode ( “N th pointcloud display”) then we could use the SetObjectDisplayMode command for certain objects (although it would be better to have the ability to define the point density on an per object basis)
We would have a very nice system that could boost performance by magnitudes !!! when working on complex scenes!
Edit: Sorry, I just saw that this is a R5 tread…