Sorry to hear about the crashes you’re encountering when using Cubase.
These crashlogs don’t look good but my intuition is that there’s something wrong here that is besides Cubase. First BSOD is related to hardware, usually you can see it in the same screen as it often points to a component name and therefore the real culprit. For now, make sure all your hardware has up-to-date firmware and drivers.
Second, if Cubase is crashing when using Nectar 4 then we can highly presume that this is due to Nectar. I would suggest you send these DMP to iZotope, maybe they can make more sense of them that we can here.
WHEA Unrecoverable error is indeed a hardware error (WHEA = Windows Hardware Error Architecture), but is also a pretty generic stop code, the dumps don’t provide enough info to see what the problem is: they look all different. The one in Cubase is a heap corruption, the others I can make a wild guess about memory corruption or dangling pointers.
The dump saved by Windows might provide some insight on the actual hardware involved, they are saved in C:\Windows\Minidump - you can check it out with WinDbg Preview (free on the Microsoft Store) or you can upload it to a service like Dropbox, WeTransfer, etc. and PM me the link, I’ll have a look.