I don't think there is a workaround, since multi-classing generally takes away restrictions.
this may not be as requested but i'm just throwing it out there. is there a way to prevent multi-classed characters with a kit from losing any weapon restrictions? With my own kit that i made, only a handful of weapons are available. as soon as i multi the character as a fighter/mage, the restrictions disappear thus making every weapon available. i can play by my own house rules and just put the pips where they are supposed to be, i was just curious if there's a work around.
ok, i figured it was a shot in the dark. i'll just continue with my house rules then.