I did my homework checked wiki as well as previous threads. I could not find recent threads, so just want to be sure, the rules have not changed.
If I have two tickets for connecting flights with different PNRs, I can get on-line BPs 24 hours before the first flight for the first flight, and 24 hours before the second flights for the second one, yes?

A special question: I take a one-stop flight from MDW to SNA, the stop is at Denver. I have two tickets: one ticket for the MDW-DEN leg, and another ticket for the DEN-SNA leg. Having the same flight number could cause any problem at on-line check in? (Do I have to leave, and reboard the plane at Denver? I would do it with great pleasure-)