Personally, I don't think LGL would have an overall very healthy effect.
Bayo doesn't actually grab the ledge THAT often during this. Like, more than usual of course but not much. She mixes it up with ABK onto or into the stage, double twitch twists, rising aerials, etc. To the point that finding a number that efficiently hinders this tactic without actually leaking into other aspects of play would be difficult.
As I stated, ledge camping is a viable strategy not just for bayo but other characters. Villager, WFT, Jigglypuff, etc... In some matchups, it's their only real way to play at times. And some players have taken to ledge camping when in ding dong or other specific kill confirm percents. (Though I doubt that adds too much to the number)
Secondly, there are characters like Mario, Sheik, Diddy, etc which effectively force ledge grabs. So there's another potential issue with too small a number.
Overall though, there's not much by way of rules you can do to hinder this tactic in my opinion. Bayo's not exactly an easy character to timeout, either. The best solution is developing counterplay (where possible) or hoping Nintendo steps back in.