I guess is just varies wildly from crew to crew. My experience IAD > NRT > BKK in J (6 months ago) was as soon as I sat down, took it off and kept it off for the entire flight both legs. Crew did not say anything to me during drink/meal service. Now I wasn't parading around the cabin and kept to myself the whole time so maybe the low profile was the reason. Friend of mine flew the same route one month before me in economy and had the same experience. In a couple months, won't be an issue for those who wish to mask and those who don't.