If you're referring to my post, that was KE flights booked through AS. They charge 120k RT to SE Asia in J on KE. It's kind of a sweet spot in the program (I even get to stop over in Korea for free, so I'm doing a week in Seoul and a week in Da Nang). But you can't transfer any of your CC points to AS so that doesn't really help you directly; it was just an example. KE is a skyteam airline; I'm not sure what other skyteam airlines would charge for a similar award. DL is the US-based skyteam carrier; they are a transfer partner for Amex.

I would check all of the following:

See if you can book on SQ. You can transfer from Chase and/or Amex. They are Star Alliance but they make very few premium awards available to partners; you have a much better chance booking with them directly.

See if you can find JL partner-bookable space. If you can, you transfer to BA and book it that way. You can search on AA or AS to try to find this space (they allow searching without having an account; to search on BA you need to open an account). Theoretically CX space might pop up in this search too, but right now that's basically impossible.

See if you can book a KE award through DL.

I'm not sure if EK flies there, but if they do search their site for space. You can transfer from Amex.

Search ANA. I see that you've already done that.

I'm not sure if I'm missing anything (I'm sure I am). Use flightconnections.com to see which airlines fly there. Remember that most programs allow multi-partner awards, so you can book connecting flights across different airlines in the same alliance. Another way to get there using oneworld carriers, for example, would be to take JL or AA to Tokyo, and then MH to Vietnam via KUL (MH does not fly to North America any more but they are good for getting to Southeast Asia from East Asia; though you will need to add another connection in KUL). If you can book something on AA that includes a different carrier, you can probably also book it on BA. So for example if you see a JFK-TYO-KUL-SGN award on AA you should be able to book it with Avios as well.