This is a good idea. In fact, I have a small macro that creates a new macro, adds a keystroke trigger, and selects the macro name field. It would be trivial, and a good idea, to include inserting a comment in that macro.
I’m not concerned about inserting above the first action, though it is often a slight annoyance (any special case is). I was just commenting originally that inserting before the first action is problematic — didn’t mean this to blow up.