I don't know an easy way to do this. My guess is that you'll have to trace the specific places that make reference to that field. Are they looking at a specific property? Are they opening the object definition from the database? Are the rules in question final? You might get lucky and there is a single, easy to access place. like pxCurrentStageLabel, but you may also find that there isn't a good hook and you'll need to create separate stages. Perhaps have the flow for Stage B call the flow for Stage A as a subflow?