It's only 'windfall' if you actually withdraw a sum from pension during iva, so if left in pension pot, even if its actually 'available' to withdraw, it isn't included in iva, is that correct?
In theory ---- however, the same could be applied to PPI refunds, in that they are only available if you claim them. With the new pension rules it will be a matter of time before creditors start looking in that direction, unless safeguards are put in place.
Many arrangements ( as mine did) have pension pots and proceeds specifically excluded, so always worth discussing at the outset and checking if already in the IVA.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014