Because the first one told me I was only allowed an open jaw or a stopover. I pushed it with her for a minute or 2, but she was firm, so I hung up and tried again. Got a gem of an agent on the 2nd try.

I'm not saying it couldn't be a more painless process, but I booked 8 segments on three different carriers with an open jaw and a stopover. I'm okay with that being a little bit complicated and taking some time. The only real complaint I have is agents who don't know their own routing rules, but that seems to go for every airline in the US (and particularly at US).

Another quick question - I'm now considering lengthening my connection in FRA from about 6 hours to about 12 hours for a mini-stopover in FRA. Within 24 hours of booking there should be no fees/other consequences associated with doing this, correct? If it matters, it'd be the same routing on the same carrier, just different times.