I haven’t seen any explicit information for US citizens in this forum about getting hitched in Taiwan. Maybe because the AIT maintains a clear and simple page on their own webpage: ait.org.tw/en/uscitizens/marriage.asp
I noticed that on this very page the AIT states that:
“Unless otherwise agreed, the father gets custody of the children”.
BS. And contradicting entirely the US Department of State web page on child matters in Taiwan.
“CUSTODY DISPUTES: … by law the custody is granted to the mother unless there are known facts of inappropriate behavior, mental or social problems.”
Which is more accurate. But the same page also includes glaring inaccuracies.