Wanted to add an updated experience report to this thread.

Pickup @ GVA is pretty easy on the Swiss side. Just walk to the end of the terminal and all the car desks are right there. There is no aisle, you are just assigned a car. Status doesn't seem to matter either as I was assigned my reserved class as an Executive Elite; only benefit seemed to be a slightly faster checkout given my profile automatically filling out certain information. You can walk to the parking garage where all the cars are (P51 deck) and it takes about 5 minutes, but there are stairs so that's tougher with lots of luggage. A shuttle is supposed to be running every 10 minutes but on both ends of my trip I waited 20+ minutes for it.

As with most European locations, pre-existing damage should be noted on your rental contract, but best practice will be to do your own walkaround before you leave the garage with photos and/or videos to make sure you don't see anything extra. It's hard because the lighting in the garage is very dim, making it hard to see damages.

With an Intermediate reservation I was assigned a Volvo XC40 B3 (smallest gasoline motor), classified as IDAR.

Photos show the other cars that were around - Opel Astra, Renault Arkona, Opel Grandland, Opel Mokka. When I returned I also saw a Polestar 3. Not sure what class those respective vehicles are.