Good day, Mr. Jdlrobson. Yesterday, after hours of experimentation, I implemented an alternative to MW's standard Navboxes in the form of this Collapse Widget on my Referata wiki, The Dixwell Dossier. (Inspired by this StackExchange thread from July 2013, and this answer by "DavidLin".)
I'm already aware that MobileFrontend can't support Navbox because, as I've heard, it's too clunky and unwieldy for mobile. As such, I came up with an alternative that's supposed to be backwards-compatible by design. On the regular MW, the prototype code's "Expand/Collapse" function works with no problems (as is currently demonstrated in the Sandbox on that site), but when seen on the mobile view... Nothing happens. "Expand" is unchanged and unclickable, and the items that are supposed to be hidden below are exposed to view.