I’d like to see a feature where smaller airport can be made useful by way of connecting flights and or demand pooling.
Example of connecting: any airports fitting the infrastructure/traffic profile of 2/4 and lower are allowed to connect and pick up passengers (ABCDCBA) from other airports of the same or lower demand. If a flight is made to an airport of higher infrastructure or demand (3/5+) then it must be direct (ABA) or any stops will only be for refueling.
Example of pooling: Daily demand is shifted to a flight when it’s being operated. (1, 2, 3x weekly etc) this can work to serve smaller airports or LH destinations that have poorer demand overall as well as encourage more efficient use of slots and aircraft assets.