A FlyerTalk Posting Legend
Join Date: Sep 2012
Location: SFO
Programs: AC SE MM, BA Gold, SQ Silver, Bonvoy Tit LTG, Hyatt Glob, HH Diamond
Posts: 44,324
Ah that's a good point. I've seen that.
But I've also had experiences flying A-B-C-D-E-F-G-H where it will check me in from A-D, but then I can go back with D as my origin and get D-G, and then again with G as my origin for G-H.
The only consistent inability I've had is when I depart my first city multiple times in one day on one PNR, since it has no way to disambiguate which segment you're trying to check in.