Pokémon XD- not enough boxes+ Trade possible

On this site, Pokémon XD has 3 boxes. However, there are actually 8 Boxes in the game. Plus space for 45 additional Pokémon in the Purification Chambers.

In the GameCube disk version, post Lugia, you can trade with all Gen 3 games, assuming they also meet their requirements. This means the entire Gen 3 National dex can be traded in. (Of course, this feature is disabled on the Switch 2.)