And then look at how equipping in general is done and do the same from bank if equipping from bank is toggled.
Something like this though I'd be very careful and thoroughly test it.
A couple of things I'd consider.
Making sure they're only equipping 1 item per slot.
Make sure they don't lose items in the process. ^ If check above is done correctly this shouldn't be of concern.
But yeah probably a few other things but I just don't know off the top of my head.
I'd help you but I personally don't know to much about 500+ revisions.