Awesome, I am glad you like it already
If I understand you correctly, then what you are asking for should not be a problem. You’d first create the menu, as shown in the original posting above. That would “automatically” create the menu class instance for you as return parameter. You can then use this menu instance to show or hide the menu as you whish, simply by calling the respective Show/HideMenu BP node. Does this answer your question?
The basic issue is that (as for now) we need to submit a BP-only asset for the marketplace. It seems we cannot mix BP and C++ in one project. It should however be possible to call the menu system BP nodes from within your C++ code, as usual, even though I have not tested that yet. I hope this guides you to the right direction: How can I call a Blueprint function inside C++ code? - Blueprint - Epic Developer Community Forums
Cheers!