Don’t know the exact but for large aircraft I would do 1 large checkpoint for each gate, and maybe 1 for every 2-4 medium gates depending on if you will be taking a lot of smaller medium aircraft like Q300, BAE146, and CRJ aircraft or a lot of 757’s and 767’s
To add a note here, I have tried several scenarios on this topic, and I get a lot of “This plane cannot land because a check in desk is unavailable” or This plane cannot land because the gate still has a plane in it (and there are 3 open gates next to it)
I now use the double check in desk and I assign 2 desk to each gate (every other one to reduce check in desks)
One thing that does help is the automated check in kiosk. But I have been having a lot of trouble with them as well as hundreds of people use them, but when they are done, they sit there and cannot find their way to the gate, while others are going right to it.
Unity pathing is complicated, and I am sure that the guys are trying to calibrate about 1000 things so I would give it some time.
Finally, I have noticed that over time, like 6 months (game time) everything starts to work and the pathing errors and desk errors and things start to go away.