I have occasional hangs while rendering w. Cubase 10.0.30 and VEP 7 for the last 3 versions.
I do_not have slow loading or unloading. The initial build of VEP 7 did unload more slowly in general.
It looks like a big stuck note on the VEP side. I have to restart the computer to get a successful render.
It's not a gigantic project in the sense which was mentioned (this latest has 90 channels in the VEP mixer) but there is a lot of active automation with these projects.