We will fly our first Allegiant flight in January - 3 of us traveling on one PNR and 1 person traveling on a second PNR. (We were forced to buy them that way because only 3 seats were available in a lower fare bucket.)

My question is mainly about the procedure for OLCI and seat assignment. If I check in at precisely T-24 hours, will I be able to freely select any seat that a passenger hasn't already paid for? Or will most seats still require payment?

It is not essential that the four of us sit together. Sitting in pairs would be nice, but even that isn't essential. My main question is whether the system would show us 4 middle seats and an upcharge for anything else, or a mix of available seats that haven't been already paid for.

I realize I could hedge: pre-select one to two aisle seats and pay for them right now. I'm just trying to understand the behavior of the OLCI software to determine if it's worth gambling on getting them at T-24 for no additional charge.