Some additional info. MCT is 90, I'll have 80. I should have no problem making the connection because I want to depart on the same aircraft on which I arrive. Just called AA RTW desk. They said that the system won't let them do it even though the AAgent acknowledged that I'll almost certainly make the flight.

Any input? Maybe I can bypass one level of checks by booking it as an open segment then adding the specific flight booking later?

It's 24 hours until the next flight, -- once daily service.