A moderator may move it to the dedicated Singapore FT forum where it might get a better response.

Tough call, though I don't recall airport security at SIN being the circus it is stateside so I'd want to venture it is possible, though others here way more familier with SIN will add their input. However if your even 15-20 minutes late arriving on SQ, which isn't unthinkable, your connection is shot so I would play it safe and rebook for the next a.m. Just my opinion...

BTW, welcome to FT.