Similar to the VFX toggle button, would make seeing the damage for one specific unit MUCH easier in the sea of indicators when even just a few units are placed.
Another thing, which to be fair I'm not sure how many people would actually care about, but having a sort of menu for damage indicators/which show would also be great. E.g. All, Hits, DoT, Criticals, Reduced Damage, etc.
Maybe even an option to pick which enemies show indicators (like in the Stage Info screen)