I suggest 1 powder. The last thing you want to do is get the data mixed up.
Also how many rounds do you think it's gonna take to develop a favorite? You will get around 1500+ rounds depending on the amount of grains. I don't like having half full powder containers with no plans of using it. I use W231, (HP 38) or Clays. (Reminds me I still have Trap100 that must be loaded and disposed of properly)