Slightly different situation. Looking to fly IAD-BKK in KE F. The booking engine shows a combo with a 45 min connection. KE 94 arr 16:30 and then KE651 departs at 17:15 on a 773ER with the original Kosmo Suite. There's also KE 659 that departs at 18:50 which is the A333 with 6F sleeper seats.

Is such a short connection possible?? According to ExpertFlyer it looks like MCT is 1h. Obviously I'd prefer the nicer seat. If I take the chance and book the earlier flight and miss the connection do I just automatically get transferred to the later flight? Would the system even show me this combo if it was not allowed?