Coaching box after a T

[Bad Zebra]

Don't believe there is a specific rule addressing that, but as an official you have the authority to determine if moving the chair creates a safety risk.

The way you're describing it, he moved his chair closer to the side line? If there's not a sufficient amount of space between his chair and the sideline to safely inbound or move down the court in transition, I'd tell him to move the chair for that reason. If he won't, whack him again, then his chair becomes empty and move it back.

If there's enough room on the side, let it go. It just singles him out as the biggest A$$ on that bench.