Can't customize shortcuts of commands configured without an explicit Placements using VS's keyboard settings

If you configure a command like this:

public override CommandConfiguration CommandConfiguration => new("%MyExtension.MyCommand1.DisplayName%")
{
    Icon = new(ImageMoniker.KnownValues.FindInFile, IconSettings.IconAndText),
    Placements =
    [
        // Solution context menu
        CommandPlacement.VsctParent(new Guid("{d309f791-903f-11d0-9efc-00a0c911004f}"), id: 537, priority: 0x0300)
    ],
};

It will show up in the keyboard settings, allowing you to define and change its shortcut.

But if the same command is part of a sub menu, like so:

 [VisualStudioContribution]
 public static MenuConfiguration Menu => new("%MyExtension.ExtensionsCommandMenu.DisplayName%")
 {
     Placements =
     [
         CommandPlacement.KnownPlacements.ExtensionsMenu
     ],
     Children =
     [
         MenuChild.Command<MyCommand1>()
     ],
 };

The command won't show up.

Start by reproducing the two configurations using CommandConfiguration, MenuConfiguration, and MenuChild.Command(), then trace how commands in submenus are registered for Visual Studio's keyboard settings. Done means a command included in a submenu without an explicit Placements entry appears in keyboard settings and its shortcut can be customized.