There’s a guy doing shoulder presses in the squat rack
When you are lifting heavy it’s safer to do it there, that way you can just focus in the upper part of your shoulders and you don’t have to worry that the muscle failure will make you drop the weights on you.
But when there’s a line to squat I think it’s a little rude
How heavy? If it’s over 1 plate there are not a whole lot of places to do a good standing overhead press without wasting energy getting the bar up except the rack imo.