The mixer FX rack seems to be broken in my installation. I followed exactly as said in the included pdf's instructions except I installed the bleeding edge version of SWS after as of the time of posting this (I really hope that's not the cause).
Code:
...(tracks named '--RACK01--' and it's children) in MCP.lua:169: bad argument #1 to 'SetMixerScroll' (MediaTrack expected)
This occurs when I interact with the FX rack before pressing F to remove it again.
Footage of it happening:
https://streamable.com/zaqwg
Another issue I found is when you are in inspector view and you select a folder:
https://i.vgy.me/5BRI6U.png
This could be an issue with REAPER 6 or 6's new theme, though. Not so sure.