What a crummy plumber, he was probably a construction/remodel type plumber who didn’t care about the customer and just wanted to go in and do whatever mechanical chore he had to do and leave.
He should have asked you into the bathroom, showed you how it works, and then you and he played with it until it was where you wanted it, and then left the directions from the box with you
Yes. It would have been nice, but I have trouble even getting a plumber to unclog a drain, which I only resort to after I have spent a couple unsuccessful hours with a snake.
I have to take what I get, and in my nanny state, any plumber I can get is probably concerned with Code Nazis breathing down their necks.