I rest on the end of the fingerboard every so often. I rest on the neck pickup a lot of the time but I also use the end of the FB and the lowest string as well. I have gradually incorporated the floating technique into my playing and it's crucial if you want to get away from the standard positions (wherever there's something easy to rest on).
If I'm resting on the low B and I have to play the B, I end up floating for a while until I can return or I just go back to resting on the pickup or FB. I've also figured out a way to rest my thumb on the top of the bass so I can get out of the way when I play the low strings. That's let me open up the possibilities even further. I think being stuck to one spot can be limiting.
One of my favorite end-of-the-fingerboard thumb resters: Anthony Jackson
He sets his action in such a way that lets him play hard down at the end of the FB without the string bottoming out or clicking like it would on most basses. I've experimented with this setup on one of my basses and it has made a big difference.
To give you a basic idea of how it works, you start with a neck that's as straight as can be. Then you to raise the action at the nut (ever-so-slightly). This step is a clincher because it requires you to modify the nut with shims and/or replace it with a whole new nut. That's a turn-off for most people. Finally you lower the action at the bridge a little. Now when you play hard near the FB, the notes don't bottom out as easily because you've got clearance on either side of the string rather than just on the bridge side.
He first explained it in a Bass Player article from last year, I believe. He and Joey also went around and did some clinics about this too, IIRC.