With core battle engine I can use <Display Text> and <Display Icon> in the skill's note box and it does pretty much what I want it to do but there's still the black transparent line that shows up at the top. I'm just nitpicking at this point though, it works well enough that I don't think there needs to be a new plugin anymore. Thanks for your help, I missed those notetags before!
I just successfully tested having events check if specific actors are in a particular party slot and then changing image to match. This will let me make scenes take into account who is in the party at the time and arrange them accordingly - this is important since I'll have extra actors beyond current party. The script used is the same from MV and is compatible with my current core plugin setup in MZ. Thank goodness.