Haven't done a lot of of PS DH's so wanted to bounce this off some people.

I just picked up a charter where I deadhead out the first day.

They put me PS on the 2nd (of 5 available) flight that day to give me almost a 20 hour layover. Take off on day 2 isn't until midmorning, so it isn't like I've got to be there crazy early. The next two flights after the one I'm on are RJ's, then a mainline. Any reason I can't move down two more flights and take the last RJ flight with a mainline back up? Or have I just answered my question and they'll only count mainlines as the flight and the backup flight...?