Had this pre-made device in a Strat years ago, made by a guy who's web site was full of great ideas/info/mods. Sold ones for Tele's and bass as well.
His small creation was mounted on/replacing the pot end of the tone knob, inside the cavity, and gave many tonal variations and PU choices by simply turning the multi-indented knob.
Not up on the TBX or DTC, and another product by StellarTone(?), but are (possibly) very much like my now mystery device.
I deffinitely want another in my someday-to-be CV Strat, but have had no luck yet finding the name/number in my file of stuffs & computer archives..., typical.

Sound familiar to anyone?
I think it's still made/sold, and was quite popular with insiders.