Wavelab 10 seems to continue to have a struggle with running plugins (even the latest release). The plugins are a pain to operate in Wavelab because any user action is very slow and adjusting parameters using plugin gui controls is random/haphazard.
Wavelab 9.5 was much smoother. Something needs to be done. I am running Wavelab on a 2019 iMac with core i9 (latest version of Mojave and 32 gb RAM). Wavelab performance is pretty far from ok currently.