I have the last version of Wavelab 7 on a Mac Pro 12 core mid 2010.
I have charged SPL vitalizer vst plugin, and Sonnox native (original EQ) and they have problems with graphical interface in Wavelab 7: when I put the mouse on it and I try to change the values, the graphic go visually down and the changes do not correspond to the position.
I notice too that the version 7 is more instable on Mac, I have sometimes crash that were impossible on Windows XP and version 6 of software.
You can drag the command-bar (where presets etc live) from the top to the bottom of the window… this seems to help on PSP plugs, might work for SPL.
Also many plug makers have managed to put updates in recent months, maybe due to these kinds of things. I’ve seen more than a couple of them fix the issue.