Yup, 63 Reverb Boss pedal.
I'm relaying from first hand witness from talking with Bobby and seeing the rig.
He used to run the BB after his wireless unit. Now running after as final sweetener.
Having used tube buffers I can confirm that they work well first (so the guitar can see it), middle (after fuzz), end final sweetener.
In my experience, no challenge to Brad or Bobby, if running wireless, the guitar never sees the tube buffer and sounds better at the end.