Being Able to Send Pokemon to Fields After Adoption

Ever on a shiny/albino/melan hunt and want to adopt a pokemon in the shelter, but don't have room? Have lots of legendary eggs in your party that won't hatch in a while? It would be a good idea, that instead of having to put pokemon you adopted from the shelter in your party right away, you could choose to send them to a field, like in a trade when you have to collect the pokemon.

Oh. Well, I still think it could be usefull.