I would like to give my custom droideka unit a second primary weapon (so that the player can switch between the regular repeater and a new custom repeater.) Even when I reference a second primary weapon in the droideka's odf, however, I cannot switch to that weapon.

Something tells me that this has to do with the droideka's combo file, but I can't seem to find that anywhere. Suggestions?

A droideka doesn't have a .combo file - only melee weapons have .combo files. Regardless, the droideka is a pseudo-vehicle, and vehicles can only have one primary and one secondary.

Oh, that's unfortunate. I guess I'll have to make my new weapon a charge-up version of the repeaters or something.