Originally Posted by Adam Smith

If you don't want the PY upgrade, keep a close eye on the upgrade list when check-in closes. If it looks likely you'll be in PY, you can go to the gate and ask them to remove your upgrade request. You only have 5 minutes between when check-in closes and when the list runs automatically (except in the case of intervention by an agent), so don't dawdle, but it's easily doable.