If anything, I think that the custom options in wind, magnet and what have you need to be more explicitly stated. Tims service is really flexible. You can get pretty much anything you want. Want an AIII crawler wound to 9k instead of 15? I have no doubt that he would do it (he may advise that its a bad idea or point you toward a better option, but it could be done!)
For example, my bridge BKPs are a warpig, C-Pig, double hex blot painkiller, a 23k double screw pole miracle man and an uber-sinner with zinc/steel base plate.
Only one of those pickups is actually a stock, as-advertised Bare Knuckle.
My pickups pan out like that because I talk the pickup out with Tim, ask questions, get answers and settle on a design.
Most people just order an as-advertised pickup off the site or buy them from a dealer.
I think the customisations need to be more heavily emphasised. Cos you can get any sound you want out of BKP. You just have to ask :P