VST3 in both. Using VST2 exhibits similar behaviours.
KVR got back to me pointing at For anyone that's getting spikes in Cubase 11 on Windows 10, 11 which prompted me to disable the Steinberg power scheme and set everything in windows. No difference. It’s the multiprocessing check box that really makes the difference. But it still doesn’t get over weird UI behaviour in Synthmaster - no cpu usage displayed and…get this…the top Synthmaster patch displayed only displays anything selected previously! I’m more or lsss resigned to using Cakewalk for this synth because it’s flawless there.