I have heard that when a girl is sent on a "date" its important that she and the male stays in a designated "mating room" at all times.
Why is that so important ?
The obvious reasons i can think of is to keep her from meeting the rest of the cats in the cattery, and also if he or she sprays to keep them from peeing all over. And also it may be because its easier for her to relate to a smaller area when going to a new place.
Is there any other reason why this is so important ?
We do not leave queens with the stud during mating periods, so I do not see why it is viewed as "important." It will be interesting to read the answers. Obviously, any time apart is a potential missed mating. However, our observation is that a reintroduction tends to result in a quick mating and may mean (although I do not know) more matings. We always make sure the girl has a defensible place to be even when in the room if she wants it.
It sounds like you're talking about a cat from another cattery visiting for stud purposes. In that case I wouldn't want her exposed to all the other cats in the house for health reasons, but, like Jan, I don't confine my girls with the boy around the clock. My boys are in rooms and I give the girl the opportunity to leave....some are happy to be "freed" and some say no thanks, I like it here

I also agree with Jan that absence often results in a quick mating.
I would be very reluctant to send a queen for stud service where the only choices were being with the male or exposed to the other cats. Some queens and studs just do not get along and some need time apart when not intensely interested in mating. I would not want to get back a traumatized queen who felt in danger and could not get out of the room.
I just had to ask, because another breeder said to me that she did not want to send her queen to a stud unless they were locked up in a room just the two on them. I was embarassed to ask why because i did not see her point, and found it a little odd.
I also became curious because i sent my queen to a stud, and they did not get any offspring. At that place my girl roamed free with the other cats, i sent her there before she came in heat so she could get accustomed to the new surroundings before "the action". (She is quitting as a breeder and all her other cats are neutered)
She blended in with the pack just fine, and from what i heard they were not lacking effort. It was more of a problem "where to put it" from what i heard. They were both young and inexperienced, the stud was less than a year old. And she have never been with a stud before.
I will just ignore that other breeders comment then

. I just wanted to know if that was something i wanted to ask for next time we try, im sending her back in a couple of months.