Has anyone used a mobile vet for multiple animals on one visit?

Hey y'all,

So I'm doing a little research into mobile vets. I have multiple cats, some have fallen behind on their vaccinations and it's kinda tricky/expensive for me to get them to the vet. I don't have a car cause I live in a big city so my options are kind of (a) use the bus which tends to be miserable for them, (b) pay an arm and a leg for uber both ways or (c) inconvenience family members or friends for assistance and be limited to their schedule.

I understand that mobile vets will usually charge you for whatever services plus a house call fee. My question is, is it standard practice to charge a house call fee per CAT or per VISIT? Obviously I'd still be charged for the services for each individual cat regardless but if it's standard practice to charge one visit fee it might be cheaper and more convenient to do in home vet care.

I appreciate any insight!