When using this code to hide commands on the main menu of the Diagram Toolbar, I found that the "Format" and "Action" DiagramCommandRange are swapped. So when I indicate the Format range, I get the commands for Action and vice versa.

manager.Toolbars["Main Menu"].Commands[(int)DiagramCommandRange.Tools].Commands

manager.Toolbars["Main Menu"].Commands[(int)DiagramCommandRange.Action].Commands