Still find that part shady for a bunch of reasons:

- What happens if the user changes providers, without having registered or withdrawn the accumulated zaps from the first provider? Are they lost? Will 1st provider allow user to register and witthdraw, now that his profile shows a different provider? If yes, sounds like manual step.

- When user changes providers, should the 1st provider still continue accepting zaps, even though user profile stops pointing to it? (Other users whose clients didnt get the latest profile changes may still see the old link in profile)