And it's not just the PPI refund, there's also the 8% simple interest you get back too. And on which you get taxed - but if the whole lot gets sent to your IP because you're in an IVA, and you forget the tax issue, you could find yourself with an unexpected bill.
For me, it should be:
If the PPI claim is against a creditor, it goes into your IVA pot.
If the PPI claim isn't against a creditor you should pay it into your IVA pot anyway to help clear the debt.
You should get the 8% interest, and it shouldn't be treated as a windfall becauise you're taxed on it.
There should be a time limit (say, two years from the final report): otherwise, people who completed five years ago could be asked for any PPI refund, to settle debts which have been written off, sold on and CDOd (I read Peston's book - sorry).
I accept that others will disagree with me on this

Gary