First I admit, always stock up on trips out of Thailand; Indonesian or Guatemalan, are favorites.
Problems I do have with Thai coffee. Thais favor light, medium, or very dark roasts. I like dark roast but not an espresso roast. Secondly with all the different brands, different coffee farms packaging their own, It is tough wading through chaff to find something you like. As you said it can vary widely. believe I will start more online ordering, even though I would rather buy from shops, or ask Flo about a couple they sell. All that said, they're getting better
Hot season escape, just stop in a supermarket before you fly back.