Minor Menu Mods

I put this offtopic as it's a blue sky feature idea.

With the root-menu in openbox (actually any multi-level menu), I find I go to a sub-menu (eg preferences), and then all-too-easily/often, while I'm moving the mouse to the item I want in the sub-menu, I move the mouse over another top-level menu, changing the submenu.

eg, I go to "preferences", then while I move the mouse towards "Openbox config", I accidentally move the mouse over "System", which then changes the sub-menu to "system"".  The mistake is made easier to do, by the fact the sub-menus always start with the first item in the list lined up with the top-level item.  You need to move the mouse right, and then down, to get the right item, but it's natural to move the mouse diagonally right/down, and then you end up changing the sub-menu.

Is it possible to have "sticky" sub-menus?  ie I click on "system", and the system submenu stays until I either select an item, or click another top-level, or click the desktop to get rid of the menu entirely.
Indeed the obmenu itself could be sticky, staying put on the desktop (under all other windows perhaps) until you right-click the desktop to dismiss it, or bring it to where your mouse s, and to the front, etc.