I live in Myanmar and have done the 70-day shuffle off to Bangkok many a times. I get another business visa on landing back in YGN every two and half months.
I'm planning a Thingjan vacation in which I'm going to fly to Kunming, China, and then work my back to Myanmar and cross at Muse, Shan State. The information online is outdated; it doesn't even reflect that that area of Myanmar has even been opened to un-accompanied foreigners recently.
I know I could enter at Muse on a tourist visa, but can they process a business visa on arrival at that crossing? Can I get one before I leave for China?