MIMF

I read somewhere about a CC pickup being made that had a coil tap so that you could add a switch and get a slightly different sound, or simply wire up the tap that you preferred. I can't for the life of me find it now. Any ideas?

I'm pretty sure any of the pickup makers doing these pickups could accommodate a tap for you.

I believe CC pickups are single coil, so do you mean a tap to split the winding? So like after 5,000 windings you insert a switch and then do 5,000 more windings?

I've never heard of that, but the best CC pickups I've ever used are from Pete Biltoff at Vintage Vibe Guitars. He sends them to you with an extra set of magnets, so you can play them with Anilco II or V, for example. He also will build you pretty much whatever you want for not too unreasonable a cost. I have never heard of a pickup like you want, but Pete can probably build it for you.

I found the one I was looking for. He quoted me an no-VAT price because I am outside EU, in Canada. https://www.rautiaguitars.net/ccbar.html