I've been looking into check in and lounge times for our BA F return from Singapore early Jan.
As I understand it (for BA flights) there is early check in row 4 T1 from 14:30 to 17:00 (Changi web site)
There is also a SATS premier checkin in T1(open 24 hours?) and T2(?).
The OW site says the QF lounge is open from 14:30 and the BA lounge from 15:00.
I need to confirm all the above nearer to the time as we need to go to the airport as early as possible within reason.