Innitially, each cat is out a minimum of two hours a day (unless they do not want to come out). Once they become familiar with us, the space and other cats, they are out permanently. This takes cat from no time, to up to 5 days (for really shy cats), to be fully integrated out in the room.
Integration happens with a lot of play, feeding them together, and distraction. Being calm, moving slowly, and creating a relaxing environmant also helps them adjust faster .
I have catified the back storage room for cats privacy and comfort. Scared cats go into the back room when strangers come in. Only I or my staff enter this room. The 50 hiding cubbies, toys, and play,and out love, are what bring the cats together.