CUI Context Menu For Custom Object

[Kyudos]

Is there some secret trick to getting a context menu to display for a custom object?

I've added a context (shortcut) menu to my partial CUIX and attached it to the alias of my custom object, but it won't display. I only ever see the standard "Edit Menu" from acad.cuix.

How do I get my menu to show up?

[Kyudos]

Actually, I can make a context menu appear for my custom object if I define it in the main CUIX, but them I can't add commands from my partial CUIX to that menu.

Is this a known bug?

[Kyudos]

Anyone?

Can I add custom shortcut menus to my CUIX or not? (referencing my own functions?)

Failing that can I assign functions from my CUIX (ARX) to shortcut menus defined in the main CUIX? When I try this it doesn't seem to work.

Is there any way to get my functions on to a shortcut menu?

(ACAD 2017 BTW)