By the way, I think I finally have some confirmation that the '50' limit is just a misunderstanding.
These two parts were found in the Pocket Monsters Black White Official Guide Wireless Play Special Secrets Book:
"The Entree Forest is the six Blocks of the 'Forest Clearing' connected to the forest entrance, and the one Block 'Deepest Clearing' on ahead, with one Block holding a maximum of 20 Pokémon. If there are too many Pokémon in the Forest Clearing, the number of Forest Clearing will expand. So if you leave your Pokémon befriended on PDW uncaught, the forest will continue to grow."
"Times you cannot go to the Island of Dreams" "(2) When there are already 50 Pokémon 'to be transferred' on the Friend Board."
As such, there is a 50-limit, but it only applies to the 'to be transferred' side, not the 'already transferred' one. The forest growing is also interesting to note.