As far as I know, the MacOS don’t have a Full Screen mode as Windows
Activate this in menu Workspace > Full screen view
What I mean, is that if you have a menu out of reach, switch temporarily to this mode, to grab the plugin.
- Use the scroll-wheel on an appropriate mouse to move any knob. This also scrolls the waveform underneath
This means the plugin does not grab the wheel event. You should better report this elsewhere, maybe https://www.steinberg.net/forum/viewforum.php?f=115