I agree with your conclusion, you usually don’t run the front for real to fly under the radar better. Maybe I thought about underground restaurants I’ve seen a couple of times targeting plentiful chinese tourists? I’ve been in a couple of these. Ground level, no signs, mute chinese personal, hierogliphs on the menu and just a word of a month from locals that you can fill your stomack for pennies there. Maybe they stumbled upon one such place and can’t recall where it was.