Bug -Menu - composable flyout isn't accessible via VO

[thatblindgeye]

Describe the problem

For the flyout variant of the composable menu demos (as well as the Navigation flyout variant), pressing space or right arrow key causes the flyout to open, but using VO + right arrow or VO + space doesn't (in the Navigation flyout example, VO + space activates the link as a click event). There is also no indication in the Navigation flyout variant that the flyout link has a submenu to open.

How do you reproduce the problem?

1. Go to the composable menu flyout and navigation flyout variant
2. Turn on Voice Over
3. Traverse inside the menu via VO + right arrow key, and try opening the menu item that has a submenu with either VO + right arrow or VO + space, and notice how the submenu doesn't open

Expected behavior
Either the submenus open via VO + another key, and/or some other context is provided to let the user know a submenu exists.

Any other information?

W3C has a couple of approaches for a flyout menu for keyboard users that might be worth looking into, but the examples for for horizontal menus rather than vertical ones.