Brian is using the bridge humbucker on his custom tele, so you might have some issue trying to get his tone. I would use the bridge on your tele and roll back some of the treble.
Brian likes to set his gain at the edge of breakup, ie. relatively clean when picking softly and breaking up with more dynamic picking. He often mentions reducing the volume on the guitar slightly. He usually has slap back delay and reverb in his tone. I see there’s a “blues lead tone” setting on your Mustang, maybe you could tweak that to get the tone you’re looking for.
John