No. AA interprets it at 24h.

That rule has been mentioned several times in connection with Star RTW's. Is this a difference between * and 1W, or is it just AA that has its own interpretation (I guess this question is never relevant within AA's own network)? Do you know BA's version?

No, I don't know how BA interprets it. But AA does interpret it as 24h. Ran into a stupid thing where a connecting flight was 1:55 away from arrival, so they wouldn't book the connection (2h minimum), and they wouldn't book the following day because it was over 24h (only 1 flight a day). Had to issue as an open segment and set up a diff itinerary for the one segment. It was absurd. But I went back and forth for several days with tariffs on this, and they do view it as 24h.

Impossible to tell.