I'm not sure how likely this is, but I was curious if anyone's heard of a Pet Battle addon that might incorporate a Hidden or Inactive feature in the pet journal.
I'd love for this to be an option similar to the Reputation window where you can tuck away the reputations you don't use or aren't interested in so they aren't cluttering up the panel otherwise.
With the amount of pets there are now, especially with redundant models on some of the critters, I feel like it would help organize the journal. I'd like to be able to select some to hide, sort of opposite from making a pet a Favourite, and they could just not display in the journal unless you select them to.
I'm not sure if Blizzard would consider adding something like this, so my next hope is that it might be possible on an addon.