Well, this is a good idea, but you ever played the game? In the game you just battle people, so....
The battle frontier in the game does not consist entirely of regular battles. Yes, the battle tower and battle hall are both fairly straightforward, but the others are not.
In the battle factory, you rent out pokemon. You have to improvise with what you are given, like in the idea I had in my previous post. The battle castle works with a point system. The battle arcade adds random effects which affect one or both parties (which has parallels to the beacon idea).
Not to mention that the battle frontiers in other games also draw from the idea of adding features which alter gameplay. This is why I'm suggesting more creative ways to battle in the battle frontier. Sure, there could be one or two which revolved around more standard pvp, but I think having most of them follow new "rules" would be better. We would have more variety for the server in terms of pvp. If they were all regular battles it would be like adding another gym challenge instead of making it something new and unique, as it is in the games.