, ok, I think they have kind of individual rules in Prachin. I know about someone last year being asked for money in the bank for 1 month, but I didn't get this requirement. They actually didn't tell him until he showed up to get the extension stamp and unfortunately didn't have the money on account any longer, and then had to leave Thailand in 7 days... Because of that, I always have the 400k on my account...
Last year they required many more photos including a dining photo. I think the requirement for money on account 3 months after is for retirement extension only. Basically, they ask for a lot more documents on house, marriage, and babies. The blue book must be fully copied and everyone in it must sign their page. Copy of ID cards from everyone made very correctly and signed even more appropriately. They come to visit me and ask to talk to two neighbors with signed copies of ID cards... And more...