Saw it again this morning REAL close. Yes it isn't a KC-141, got that wrong, actually did mean a 135 (707 military version tanker) but it doesn't seem to be that either, donks too big so something a bit more modern and it IS RSAF.
It was just stooging about yesterday NOT do approaches and refusals just orbiting randomly in various places for quite a while. Maybe getting the lie of the land or an aerial tour of the local sights.
Must be here for the F-16 but didn't look like it had wing mounted fueller pods. Seems strange to use this one if it can only service a small bird at a time. Someone must know a bit more.