Is it possible to swap passports while flying to apply for an ED visa in Bali?

Question is about swapping passport during a flight.

Yes, no problem, you leave with the passport you entered Thailand and swap during the flight to other passport to enter country of destination.

You read correct that you can not to this at land borders as the Immigration checks the exit stamp from the neighbor country.

The discussion:

Using all kind of different visa to live inside Thailand only creates a bigger chance to get questions from Immigration. a Visa is only a sticker in your passport that gives you a certain period of stay IF allowed to enter the country.

Is a nice discussion but off topic.

BTW...what happened to your plans to obtain the Non B business you spoke about in January 2020?

And may I ask...

How many months were you in Thailand in 2019?

Upon your return to Thailand the Thai Immigration Officer will match both of your passports. If you have a history of living in Thailand using various visas, extensions, and border runs be prepared for questions.

I’m dual UK and OZ and have done this many times by air but never by land. Usually it’s because the next country visited gives something additional by swapping passports (eg longer stay, cheaper visa cost) or simply to manage page usage.

I’ve never done anything though where applying for a new visa to the country just left from.