I wonder about the usefulness of an Act of Attainder...
Instead of trying to ram each, often very different, case/square pegs through X number of round holes, it would be better to have an Act of Attainder placed before the commons, the arguments made, and if passed, the result is then specific to that individual.
Personally i have no problem with someone being stripped of their citizenship - I'm uneasy with that power lying in the hands of a witless cockwomble like Priti Patel - but if a government submitted a petition to a senior court, or to parliament, and it was measured against an act of parliament outlining the circumstances under which citizenship could be annulled, I'd be permanently happy.