I don't really understand what you mean, we got a lot of different systems here to test with. When someone has a problem we try the one that comes the most close. Is that the one you're interested in?
Yes, that's the one. Because maybe an obvious thing like the graphic card/driver or type of CPU could be the cause of the issue.
I'm almost sure it's related to something graphical, because when I open the plugin GUI when it's NOT activated in Cubase, it also starts stressing my 12th CPU core. The fact it always and every time stresses the same CPU core in every high memory project, is remarkable itself.
Obviously when I run multiple instances of the plugin in an empty project, every separate instances of the plugin is pointed to 1 of the 12 cores, exactly like it should be in a multi processing environment.