Just a thought ...
If a shooter signs up to shoot in Production his ammo is scored as minor regardless of what he/she declares, it's not a choice, it's a requirement. If he/her equipment is later found to be noncompliant the shooter is then moved for scoring purposes to Open, it's not a punishment it's a correction. All stages shot before and after the move are scored in Open, and Open allows for the target hits to be scored either in major or minor. Since the shooter is now shooting Open he should be allowed to have his targets scored based on the power factor of the ammo he/she started shooting the match with. If it was major then all targets should be scored major, if it was minor and he switched to major after the move then all targets should be scored minor. Once he/she is reassigned to Open the shooter has the right to take full advantage of the rules for Open.