We flew with Spirit in the end of August. Masks are of course required. Depending on how full the flight is they will attempt to leave open rows in between people as well as middle seats open. Our flight arriving in Orlando almost every seat was full however on our departing flight they were able to keep people much more spaced out. I never saw any further sanitation methods taking place it didn't feel much different from flying pre-covid but it also didn't seem any worse than making a trip to the grocery store.