Frontier Scouts are airline employees so they're not allowed to accept tips. The "electric carts" you're referring to are for transferring passengers between gates on the A concourse. They won't take you to the baggage area but they can drop you off at the elevator in the middle of the concourse. I'm not sure if Scouts will be able to assist, but you can ask. Their primary function, I believe, is to assist wheelchair and handicapped passengers. If you "gate check" the stroller you'll get it back at the door of the plane when you get off, so don't check it like regular luggage at the ticket counter.