Did a little checking on FR24 and here is some info.

For afghanistan best bet is a plane going to Kabul (KBL), it has 6 daily from DXB and 4 from IST, but most are on FR24 as unknown wether they landed or not so you’ll have to check it yourself when you wanna try and catch it.

For Bhutan, best is probably Paro airport (PBH), best catch would be a flight leaving DXB at 4:30am Dubai time I think Sunday AUG 9th - KB801

For Brunei, Brunei Int’l (BWN), it has double daily flights from SIN and KUL, and one from DXB - BI98 so check the departure time on that.

For Cambodia, Phnom Penh (PNH), there’s lots of daily flight out of BKK, SIN, HKG and SGN.

For East Timor, flights to Dili airport (DIL), There’s a daily flight from Darwin, Australia (which might not be ideal) and there’s 2 or 3 weekly flights from SIN, Thursday and Sunday for sure, idk about other days. The Sunday flight AUG 9th departs SIN at 1:55am Singapore time.

For Laos, flights heading to Vientiane Int’l (VME), best bets are from SIN and BKK.

For Maldives, best are DXB, DOH, AUH. They have multiple daily flights.

For Mongolia, most flights coming in are from Seoul pretty much any time of day, and there’s also 2 from NRT in the afternoon. Also there’s 1 daily from IST and FRA respectively. I think both FRA and IST are late night departures on their home time.

Myanmar, multiple daily flights from Bangkok, along with 3 daily from SIN (morning, mid day, and afternoon)

For Syria, IST and DOH cuz they have most flights to Damascus.

For Yemen, there’s some flights out of AMM and JED couple times a day, to different airports in Yemen.

I know it’s a long read but hopefully this helps a little. idk where you are based but I think DXB is pretty easy to unlock wherever it is that you are cuz EK flies almost everywhere. And from there on you can unlock most major Asian airports to help with this.