My main idea is to bring in the Mewtwo ball - this was a pokeball shown in the first pokemon movie that has an eye in it, it was used i believe when Mewtwo captures pokemon for his bigger plan in the movie.
Screenshot reference: https://prnt.sc/uat0lp
Wiki on it: https://pokemon.fandom.com/wiki/Mewtwo_Ball
My other idea was pokeball customization, it would be nice to have the option to make custom texture pokeballs similar to custom pokemon, in a seperate folder of course and spawnable similar to pokemon with a CustomTexture spec, that way it gives more freedom to give full customization over the players experience, as well as opens a whole new door for things like particle effects and so on for pokeballs other than the premiere ball!