US Citizen Married to Taiwanese citizen -- File Separately or Jointly?

Me:
US Citizen
Employed in Taiwan
Stocks in the US

Wife:
Taiwan Citizen
Employed in Taiwan
Stocks in the US

US Taxes:
File Separately (She only needs to file for stocks…)

TW Taxes:
? Not sure, wife thinks we need to file together…

I’m not an expert, so take this with the skepticism it deserves, but I believe you can file separately if you have not filed together before.

Strictly speaking, the year in which you marry and the year in which you divorce are years in which you can choose to either file independently or jointly with years of marriage supposed to be jointly filed, but if my understanding is correct, a couple that has NEVER filed jointly can continue to file separately during their marriage.