Wouldn't be such a bad idea actually.
I guess you'd either do it by a playertype, if that's possible or by a /command.
This would actually be pretty handy. And useful since holding in place with jets to build something high-up is a nuisance, as one moment of holding on too long or letting go for too long, and you've entirely missed your spot and are falling down.
Yeah, I support this idea. I hope it get's made.
If it were a /command though, an RTB Pref would be quite handy to say whether it's Admin only, so you don't get everyone toggling it and then flying around everywhere.