Drawing a 2D image or some basic text isn't going to be any of your performance concern tbh... you won't feel any difference in a paint being drawn or not unless you are drawing 1000's of them.
Only reason that I can think of is when a scripters tries to load and paint Objects/Npcs inside the onPaint method, this can get ugly pretty fast. but that shouldn't be your repsonsibility.
Scripters could implement this is a cli parameters in the script if they want.