Hello,
I usually remove the right mouse button command on buttons that have submenus. This allows you to open the submenu with a right click and avoids having to go to the small corner at the bottom right to open it (personally it wastes my time and annoys me, it’s too small).
The middle mouse click reacts exactly like the left click. Even with a 3DConnexion type mouse, I don’t think anyone uses the middle click as a left click.
Maybe… Still, the left click and the middle click do the same thing. It would be handy to be able to open the submenu with the middle click even if there are commands defined for the left click and the right click.
jmv