...booking 2 sectors SIN-BKK on CX712 and then connecting to BKK-HKG on CX712
I don't believe that is what has been offered/bookable so I don't believe that is what the agent put in to the booking. I think you have taken that part of the OP's post too literally, for any through flight like this you can't book it as two connecting flights. The option wouldn't have been offered to the agent on their system.
Originally Posted by
Dave Noble
The CX712 flight is ticketed as a single coupon SIN-HKG and NOT as 2 coupons SIN-BKK-HKG
Yes, so if the OP books CX712 SIN-BKK-HKG then MCT is not relevant and it is ticketable. The assumption (as the OP has said it is the same aircraft they are arriving on and departing from at BKK) is that the OP is looking at changing to CX712 and that it should therefore be ticketable.
I am glad we resolved that