Most Reliable US-SIN route
 

Wanting to book an Saver F award from a US gateway city to Sidney in late December 2021. As things currently stand, I know that can easily change, what would you consider to be the most reliable route to SIN. In reliable I mean actually flying, and no plane swaps? Would that be LAX-SIN?

The most reliable is SFO-SIN in J. I believe this is still currently operating.

Your problem may well be trying to get from SIN-SYD...

Although Dec 2021 is a way off, unless you’re an Australian citizen or permanent resident, you may be barred from entering the country.

SIN-LAX-SIN had been operating the most frequencies during the (still ongoing) crisis. IIRC, even more frequently flown than SFO.

The two words "reliable" and "December" should not be in the same sentence. Whether and under what circumstances, on what carrier, schedule, aircraft, and class of service is purely notional. I would revisit December travel 30-45 days prior to your intended date of travel. At that point you can figure out what is doable.

If you find a good ticket today, don't plan on it "sticking" in any realistic way.

There is no F seat for any route up to End oct. so it might continue to 2022

I would not focus on F in the future. As service is slowly restored, the frequency and routes with F service will likely remain low for a good long while. When you do decide to travel, look at the hard & soft products for the convenient carriers rather than the class of service.

SIN-LAX-SIN: this was the only US route operating at all during the early days of the pandemic. But don't count on F any time soon.

+1, we have been using SQ37/38 to get back and forth from LAX to CGK during the pandemic, no F, but J is good enough for us.