A little background - a few years ago at Experience, Bugs Henderson told a story. He was listening to one of the other guys play, and he heard him getting what he thought was almost a single-coil sound. So he asked about it when the guy came offstage. The guy said it was the coil tap. Bugs said he told someone he wished his CU22 had a coil tap, and they reached out and pulled up the tone knob. I forget how long Bugs said he'd had that guitar, but he had no idea it was there. He went on to say he went back to his hotel room and pulled out the other guitar he had and pulled up the tap - and shot the knob across the room (no tap).
Tuesday, I was watching a couple of Rob's videos from Emil's SE 7-string demo and showing them to my wife. Emil said something about a coil tap. I turned to my wife and said, "Did he just say his 7-string has a tap? Mine doesn't have a tap. I know it doesn't...I'm positive it doesn't...I'm really sure it doesn't...I don't think it does...".
Pulled out the 7-string yesterday. Grabbed the tone knob and pulled.
I've had that guitar for like four months and never thought to try that.