Ooooooh, ok. This is, well, an unusual way of thinking about card creation, since custom cards are typically not actually used in duels at all, and 99% of the time they even are it's by the person who made them. Usually, peoples' problems with erratas are that the old cards no longer do what the card says they do, which wouldn't apply here for that reason.
If it helps, since nobody really plays with other peoples' custom cards you could treat this phase of card creation as a design stage. Like you have written up the cards and are sharing them with the rest of the design team to see if th