If the commuters are doing a favor by coming to work when they were scheduled off and agreed to work, then I say give them the PS ticket. Otherwise, I've seen many commuters wait until the last flight of the day that would get them to checkin on time and then have a fit when something happens, meanwhile, 2 or 3 flights went out earlier in the day with seats open on them. They have the ability to check loads and (excluding irregular ops) should be able to know if they need to make alternate arrangements to get to work on time (ID90s, leave the night before, etc).