I have been on R since I’ve been here (a little less than a year). As long as I’m in this seat I will be on R since there are 8 hard lines and 80 SO’s (there are about a dozen on long term medical). I’ve been awarded upgrade with training to commence sometime shortly after the first of the year. Those hired today into the A300 (for example) can hold a line immediately. Different seats, different situations.
If you live in MIA and your trip is built BOS-PHL, you would have an airline ticket from SDF-BOS. You can either get to SDF on your own and then use the ticket as scheduled or you can use the “ticket index” to change your ticket to MIA-BOS. But there is a defined “work with” fare (above which you pay out of pocket) and you’re no longer “traveling as scheduled” so if you don’t make it to BOS on time, you could have problems.
Hope this helps.
Tipsy