Thanks for your help testing this!
Yes I restarted the VE Pro Server, and Cubase after the change. I think the reason for the readout is because Kontakt can only use 1 core pr instance. It does not matter if VE Pro is able to utilize all cores, because the single instance of Kontakt cant use more than one. If you keep adding Kontakts, they will be distributed to the availiable cores, but still each instance won't be able to use more than 1 core at the time.
For this testing I've used 3 "effect" patches from TH Plucked Piano. They have lots of effects and long release time. So voices build up quite fast. Playing all 3 patches at the same time causes cpu overload quite fast. It does not matter wheter or not VE Pro can use 2 or 8 threads. This just seems to be the way Kontakt works. With multiprocessing turned off, each instance can't use more than 1 core. This is as explained earlier only a limitation when you are playing complex patches, usually this is not a problem.
And, if I let Kontakt do its own multiprocessing within VE Pro, usually I try to set it to 4 cores, there is no problem with overload, atlest not when playing back an normal amount of notes. Also, it seems to work, I havent encountered any issues, so this is why I'm asking wheter or not there are any know issues. As I see it there are no other alternatives, besides hosting 1 (complex) patch per Kontakt instance, which isnt particulary ram efficient. Each new Kontakt instance will use up a portion of ram, and you won't benefit from patches who are sharing the same sample pool, you will have to reload the same base samples for every patch as Kontakt do not seem to communicate ram usage across instances.