Bladecreep... you’re about a year away from your command, that is, if you if you keep your nose clean, and do your job. You quit now... say bye bye to your seniority number. Go to Taiwan, China, or where ever... upgrade? Not a chance. A dose of reality... an expat is one whose necessity if purely temporary until such time that a local can qualify to assume the position that you’ve been hired, on a short term basis, may I add.
If you are hired... and a big IF... it will more than likely be as a relief first officer of which the time is worthless. Nothing but a bunch of alpha numerics in the old logbook.
Another consideration... lets assume you don’t like being an expat and want to return to the U.S. You’re going to have a hard time explaining why you quit a 121 job with a command in the near future to what... be a relief first officer?
Good luck.