I don't want to do this. Let's imagine a user has a credit card expire and a payment fail, and they get demoted, but they quickly fix it - you wouldn't want all their special data getting wiped.

It would be better to solve just by some {+START,{$IS_IN_GROUP,... kind of logic around where you're displaying the CPFs. Or with some custom coding.

If there's too much Tempcode being squeezed together, you could split it up into page includes ('include' Comcode tag). E.g. have a page for including each field into the master page.