Gosh, I have seen this question come up many times over the years with no apparent "solution".
"Do shortcut menus only work from within the main CUI?"
The answer to the question... appears to be "yes (but...)".
So, assuming this is true, it would seem that if one wants to create and use a set of custom shortcut menus, and one prefers not to modify those in the "OOTB" CUI, the "custom" CUI should be loaded as "main", and the "ACAD" (plus any others) should be loaded as "partial".
I haven't been able to find any confirmation of this, but it appears to me that AutoCAD can "use" only one shortcut menu at a time (which makes a certain amount of sense to me), and (I have always assumed) it looks for it first in the "main" CUI. If there is no definition there, one might expect it to "look" in the partials loaded beneath the "main". From there, one might expect that it would go to "enterprise" and so on.
However, it doesn't appear to work this way. For example, I have the "ACAD" CUI loaded as a partial under my company "enterprise" CUI, with a customizable "USER" CUI loaded as "main". I have attempted to define an "alternate" shortcut menu in the USER CUI, but all I ever see is the shortcut menu defined in "ACAD".
I'd love to hear how this works from someone who really knows what they are talking about.
![Autodesk Design & Make Report](https://forums.autodesk.com/t5/image/serverpage/image-id/1350519iCB55845EBFC43016/image-size/large?v=v2&px=999" "Autodesk Design & Make Report")
