As a consumer, I had no knowledge of this, and when I complained, the plumber said he was not allowed to change it due to code restrictions.
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