This exact situation happened to me a couple of years ago with an SHV out and back line. Since the trips were revised outside of the 4 hr return window, they were automatically dropped and reassigned as RAT trips (125% pay but no disruption/extra duty period pay). I called up scheduling and told them I didnt want to do any of the trips so I went into SUB. They can only give you SUB trips that fall with +/- 4 hours of your original trip footprint, so that limits them pretty much to other O&Bs. They called us one day out of the 12 we were on SUB. Turned out to be a pretty sweet deal.