their law I meant private school pension law. When I checked, non regular teachers without management duties were excluded as well as foreign teachers, iirc. It is good for them if they are already included.
I checked the law, and found it is still just for regular teachers. The wording in the law is paid full-time staff employed within the establishment staffing of a registered private school. It is regardless of nationality and qualifications. You should be within the establishment staffing to be eligible to the mandated pension. I guess most of foreign teachers are not employed within the establishment staffing, even though they are licenced qualified full-time teaches with iWork permit or work right. They may be extra teachers.
Standard for the establishment staffing
https://edu.law.moe.gov.tw/LawContent.aspx?id=FL008932
https://edu.law.moe.gov.tw/LawContent.aspx?id=GL001257