Yes but not commercially, got some drama students to read through a couple of scenes of a play as part of their coursework. Not a particularly easy experience for a writer imo. But if it's being commissioned it's probably much more rewarding and quite exciting.
I'd strongly advise them to research the market first ie. Is there one? I'd be surprised if there's a business to be had here, myself. Aren't they done by Prod Co.s on scripts which have already been greenlighted for making? They do it all themselves. Can't see wannabe sitcom/other TV writers forking out for a read through if the thing's not even been optioned by a Prod Co.
Just my thoughts. You'll need another opinion because I'm quite negative on this sort of thing. Someone else might say it's a great idea and there's a market for it.
If your friend's going to all the lengths needed to select the right cast for the roles, and even direct it themselves then they might as well have their own Prod Co. IMOO. Plenty of good filming teams available for hire. Don't forget writers can use their software to read through as well, although they're not getting feedback on it. But I fancy there's no shortage of scripting feedback services now.