Honestly? I think it would be better to just pick one treatment. If you are doing copper for velvet, you don't need the tank transfers. Just run copper 14 days, and then transfer to a clean QT. Or, just keep them in copper 30 days with no transfers at all.
Why 14 or 30 days when we know that both ICH and Velvet cannot stay on the fish for more than 3-7 days (ICH) and 4 days (Velvet).