The ones I tried are both VST 2.4 (only) 64-bit (only, i.e. no 32-bit versions installed), both use 32-bit float internal precision, latest versions of everything, and both work fine in Cubase Pro 9.5.20 but crash instantly in WaveLab 9.5.20 with no crash log.
I think it might be related to how the NI plugins report their internal processing precision; e.g. as a test, I copied the wonderful Grungelizer from the Cubase folder into my WaveLab plugins folder, and it works fine, even though it’s also VST 2.4, 64-bit, 32-bit float. I also have a bunch of iZotope VST3’s using 32-bit float precision, no problems there either.
Apart from Supercharger GT, I don’t use any other NI plugins in WaveLab, and I notice Guitar Rig (which is NI’s Fx “framework”) is also on the default ‘ignore’ list in WaveLab, so I can’t test any further.