Yep can confirm, that does not work with slate plugins, but also not for KUSH, Softube, Soundtoys, etc. basically for no big name 3rd party vendor. In my case updating the VBC rack made it much better (but thats basically the only plugin I use from them these days).
Seems like you could be interested in this FR as well:
Solution to crashes by plugins - Sandboxing (Crash protection) - Cubase - Steinberg Forums
Would be nice if you could leave a vote if thats the case.