In my case 12 months ago I needed to show proof of a contract to allow me to work remotely and also the income from that contract. This was in Australia
Once you factor in the cost of getting to Vietnam and accommodation while waiting it is far far cheaper to do in Australia. Also if you are rejected for some reason you are still at home😊
The fact that you even refer to a TDAC Visa reflects a lack of understanding and an apparent lack of careful reading. Please don’t expect others to do your basic research
The tone of your post is arrogant and I’m not surprised you were looked at askance. And your 20 years of experience in Thailand reinforces my perception that you have a sense of entitlement 😳😊