Thanks for the hints, taiwanesetexan. Recently, my plans have changed a little bit, and I probably won’t use my NWOHR passport and the TARC for travelling. Instead, I plan to apply for the TARC, then stay a year in Taiwan to get my full citizenship and a “proper” passport.
For this reason, I along with several other Forumosa members, have been researching for the last couple of weeks how we can apply for the TARC in our specific case (in my case: Taiwanese mother doesn’t have household registration anymore). This is the thread where we are exchanging what we found out: Do I have a chance of getting a Taiwanese passport and TARC?
By any chance, you do not happen to know a definite answer on what to do if one applies for a TARC with AF384 身分, but without having a current household registration? What we already found out is that you do not need an active HHR, but you need to supply a 戶口名簿 which seems hard to do if your parent never kept an old one.