In case anyone is interested in the same info, this needs to be differentiated.
I own now Wavelab Elements 9 (current version v9.0.15) and I have noticed the following:
- most Cubase VST-plugins do work (especially the VST2-plugins)
- some VST3 plugins do NOT work
What I am quite disappointed about is the fact, that I can NOT use the multiband-effects (especially the compressor) provided by Cubase.
Within this forum-thread, Steinberg points out that this is not possible within the Elements-version of Wavelab: