Middle Mouse Popup - no right click

If I insert a left/right mouse action into the middle mouse popup such as this Trim/Untrim:

In the middle mouse menu, it shows up, and functions, as an additional left click underneath the intended left click like this:

Since left/right click works fine in the standard menu, is this behavior a bug, a yet to be completed feature, or not possible?

Thanks

Right clicks do not work in any standard OS X menu. That’s why the Untrim item is added to the menu under Trim. Right click works in Rhino tool palette buttons, but not in menus.

Oh, my bad…thank you.