Originally Posted by
Steve in Olympia
Judy795 wrote as follows: "You are allowed a large number of days layover in London, coming or going to your next destination (Paris). Yes, you need to call BA to do this ...".
99.9 percent of the readers of this post would conclude that Judy is telling us that a phone call is necessary to book a layover.
That's how I read it. However, unless the OP had other intent with question 2 (it's not 100% clear), I think he may be conflating the two separate issues of a layover and an open jaw.
FWIW, a layover can be taken care of online, while an open-jaw ticket cannot.
Complicating matters further, unless things have changed since the last time I booked one using a Chase companion award voucher, all segments in an open-jaw booking need to be from the same travel zone.
Edit: Ah, I see question 3 now, in which the OP goes further into the notion of doing an open jaw, which would be permitted with the Chase voucher, but wouldn't save the OP from APD with a stayover.
When we wanted to go LAX-LHR-AMS and then CPH-LHR-LAX, that was not permitted, and we instead did LAX-LHR-AMS and then LHR-LAX on the return, buying CE tickets from CPH-LHR separately.