I love the fermented tealeaf salad , too..unfortunately, if I'm not mistaken, it's got preservatives in it. Which, as a natural fermentation, it should not need. I remember buying packs of it from a local store in Chiangmai that was run by Burmese. If you must have it, surely local Burmese can help you find it.
In my case, a total of less than 150 days in 4 years, all exemptions, many entries , often short. But not throughout the year as I don't live or work in TH