You get 2 land border crossings per calendar year, on 1 Jan it resets….you get 45 days at all border crossings and 30 days at immigration for an extension…you can fly Out/In as many times as you want or until you meet that one overzealous I/O who says otherwise….
wow you sound like a salty Boomer retiree most likely because you wanted to make SM but never could…if you don’t register than dear Uncle never knew about them unless you put it on an SF86 for your clearance
until you want to take her to the USA on her Thai Passport and the Embassy asks what’s her status…then they have to acknowledge it for the visa process