I just chatted with the breeder for a few minutes (she had to go feed the babies).
Léa is definitively getting better at flying and landing - she's able to land on toys/gyms that are hung from the ceiling with no problem.
The babies are still in the intermediary cage (a large rabbit cage) but will be moving to a full size parrot cage this week.
I also asked if the babies had started to interact with her pets (ironically, also two African Greys and a Cape parrot (Léa's older brother by a few years)) and she says right now, the babies still generally hang out together but are checking out the older guys. The older ones are also observing the young ones and apparently seem to find them a bit excited. She's also seen the older birds go one at the time to feed the younger ones - that I'd love to see!