Kenny makes a keyboard shortcut that opens fx, but you could make a custom action and map it to a mouse modifier upon clicking a track.
Make the command like he makes it and maybe try and add a close all floating fxs, before the many close/open fx. This will make it, so every time you click on another track the previous open tracks will close.
If you just make the command like he does, you might end up with a lot of open windows, and would have to click again on the selected track to close all open fxs for that track.
https://www.youtube.com/watch?v=Bb-sEdXGGCc