I've routed for a humbucker in tele (neck, I'd be a bit more wary around the bridge). But I did it the "old-fashioned" way with a chisel. I started out using conventional methods I was taught in woodworking at school, but after the straight(-ish) edges were reasonably secure I got bored, and just levered chunks out instead! It worked though... (which is not something I can say about the chisel since then!)
Given my record with a hand drill, which I do enjoy taking for a spin around the flat occasionally, I think there's a good chance that I would have been "rear-mounting" my pickup if I'd used it. :lol:
EDIT: Forgot to write what actually meant to say :roll: - the stuff I'm wary of is anything that has to do with the "playing surface". I have shimmed a neck successfully, and replaced nuts with pre-slotted ones, bridge saddles, but that's about it. Any messing with fitting a neck, fret condition, moving or replacing a bridge, that sort of thing, makes me think I could turn a relative cheap job into a very expensive job quite quickly with successive, er, "solutions"...