First, I thought 20k Baht is <$600. It used to be the amount I took out after clearing customs, although I now take out $15,900 so I have lower bills for a cab. I just looked, and at an
exchange rate of 0.030 Baht/USD it comes out to $595. FWIW, the money goes into a safe and is doled out over a couple weeks so that I only have to pay one ATM charge.
Putting that to the side, I'm going under the assumption this will not impact me. But if it does, from what I am reading, one will not be able to just go to an ATM and pull out cash? I fly with almost no cash, but pull out Baht after going through security. IIRC, there are no ATMs between landing and immigration. Are there?