Go in the morning with your passport, a passport photo and 1900 baht cash, complete the form and drop off your passport, the photo and the cash. Come back when they tell you to come back. I suggest you wear pants to be safe.
I don’t think it’s a matter that some airlines ask and some airlines don’t ask. It’s a matter that some airline agents ask and some airline agents don’t ask or some airline agents ask sometimes and don’t ask sometimes. You really can’t predict it.