I'm missing majority of my VST2 Collection plugins in both Ableton and Bitwig on Windows 10
Have you checked that the missing VST2 plugins is installed and present on the same location where the plugins that show up is located?
Can Ableton Live show both Arturias VST3 and VST2 plugins at the same time, as they share the same ID? I think Bitwig can, but i'm not sure it's without issues.
when I use the VST3 plugins I have an extremely slow time switching presets that does not occur in the VST2 versions.
Please elaborate this - including what slow is.