I'm trying to do the same thing this coming December. Will arrive on SQ, then quick turnaround and head out. Would be helpful if we didn't have to clear and re-enter. Not sure what airline we will be flying out yet. Looks like a lot of people have similar situations / questions. Has anyone done this recently on two separate PNRs? I assume if there is no presence at the transit desk, if you can't do OLCI to get a new BP for your connecting flight, you'd have to exit, check in and re-enter. We won't have checked bags either.