Not to be outdone by Nina, Gustavo also has a pretty chill script for comparing character sets across two UFOs. It appears that Commercial Type has one as well. There are multiple people writing the same scripts. Does that seem wasteful to you? At any rate, here is Gustavo’s.
“A simple Robofont extension to copy selected glyphs from one open font to other open font(s).” That’s weird, I thought this script was going to do something else. Just kidding.