No NOTAMs for Loy Kratong. But the lanterns are now limited to x-size and a candle of y-duration. These laws are as strictly enforced as all Thai transportation rules.
NOTAM's issued at Swampi (BKK) when the locals launch lanterns on the approach paths to protest lack of compensation from the government d'jour.
Try Yasothon or Nong Khai in May/June for the rocket festivals.