Multiple MIDI Keyboards Controlling a Single MainStage Virtual Keyboard?

Hi all -

Is it possible to have a single MainStage virtual keyboard be controlled by two different external MIDI keyboard controllers? I have a two-keyboard rig with a bunch of concerts and patches set up with splits/layers/channels and everything works great, but there are times when I'd like to be able to strap on a MIDI-enabled keytar - sometimes mid-song - instead of standing behind my rig. (Cheesy, sure, but it's for an 80s band and Cheese Is The Way. :))

Do I need to set up another separate virtual keyboard in MainStage, map the keytar to it, and duplicate the existing split/layer/channel configurations, or is there a per-patch way to tell a certain virtual keyboard to accept input from either of two different physical controllers?

I use multiple hardware controllers mapped to their own virtual keyboards already so selecting "All" devices to control the one virtual keyboard would result in notes played on different MIDI controllers to be played everywhere.

One approach I thought of might be to create a copy of the patch and override its Concert-level controller setting for that virtual keyboard on songs/patches where I might want to swap hardware and select the patch accordingly (depending on the size of the stage, for example), but then I would have to make sure any modifications to the patches are kept in sync. Not that big of a deal, but still.

Hopefully this is possible and I'm just missing it in the manual.

Thanks for any pointers!