If you wanna fix the problem, eliminate the incentive.

Level 1 trip drop per PCS run per pilot
Level 1 Silver slip per PCS run per pilot
Treat OOBWS like a QS (1 AA window for all pilots with slips)

Senior gets first dibs at whatever they want through seniority but they don't get a complete monopoly over blue days, silvers and emptying their entire schedule to play Farming Simulator.

God forbid you're not the harmed pilot because you have to ...

*Checks notes*

...fly what you bid for 😯