Bottom line is all of these ex-SIN overnight flights suck. It's too short to get decent sleep; only marginally better than an ex-PER red-eye.
The "best option" is probably a day flight ex-SIN. 0250h departure for a 1140h arrival doesn't really smack of "next day arrive and straight to work" - more like a leisurely arrival in and the rest of the day is a write off (viz. sleep). So, big deal. At least it does give a good amount of slack for those connecting in via LCCs into SIN. (Also, you'll be able to fly a flight at a time which would have no chance of getting off the ground in SYD in a million years, if that is of any comical value to some
).
The extra incentive if you fly Scoot? The food isn't free, so you can go straight to sleep (bring plugs to block out the "Service anyone?" calls).
The Y seating is 10 across. A little tight, anyone? (Probably not if you are a fit person, unlike me).
And ScootBiz is definitely PE at best (and you all thought Jetstar Business was the industry's biggest oxymoron). (To be fair, however, consider UA J and BA CW which are also 8 across).