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Somebody asked about possibly adding the ability for Double Battles to use more than 6 pokemon, for the Psychic Fighting gym.
I coded a sort of solution for this. Basically it makes it so that any double battle that isn't technically one trainer (see image for an example) will have them each use separate parties instead of one combined party. This means both of them can use a full party of 6 pokemon.
This would mean that if you want to make the fight with both gym leaders work, you'd need to make them both separate trainers, instead of one trainer like those Gen 3 gym leaders were.
I'm still not completely done with the code, I have to make sure there are no bugs with it for things like Roar, but once it's done I'll post it and maybe people can vote on whether it's a change worth adding.