Unfortunately, there is no way to check - uncheck a menu item with the current API.
No can do.
Here's a link to what you can do with flyout menus. (Besides creating sub-menus, not much).
It could be you can cobble together something using NativeMenus, but it would not be straight-forward...
Not good news
Do you have any idea how to get hold of NativeMenu handle for the menu? Would I be able to get access to it in AS?
hmm, that won't help much as I need to intercept the menu with "close/close group" and I don't now what is the parent object to listen on mouseClick