If I like a Lead vocals plugin…and choose it in the strip, can I not also choose a mastering setting? or is it only one OR the other? If both, do I just add the EZ mix plug in into the effects strip twice..with the mastering choice last in line?
in general, you only apply Mastering Presets on the Master Fader/Bus but in the end, it’s your ears that decide.
Stacking of several instances with different presets on one track (or in the standalone) is definitely doable, it only depends on which presets you use.
Several presets with a lot of FX will probably not sound good, so you will likely not use them that way. More like some basic sound shaping and compression first, followed by more FX oriented stuff. Or keep it simple with the basic stuff on the Tracks and put FX presets on Send Busses.