Originally Posted by
paperwastage
Jewel early check in isn’t as useful for SQ unless you actually want to spend time there. Their own counters in T2/T3 will check you in up to 48 hours before departure, except USA flights.
Originally Posted by
richiealexander
lets say between those transit time, while in the lounge, im thinking to go out and visit singapore city, is that allowed?
Yes, the arrival and departure flows are mixed in T1/2/3. You can easily leave the lounge and head to arrival immigration like any arriving passenger.