I’m not sure how closely this relates to @Mataiou’s NCC complaint (did that go any further?) - maybe not very much - but I just got Chunghwa Telecom to accept me using my APRC as my primary ID rather than my passport.
I’ve had a prepaid SIM with them since 2016, which I opened using a passport that long since expired but I never got around to updating. The only real consequence of this has been that whenever I’ve topped up online I’ve needed to find and enter my old passport number.
Anyway, I finally got around to updating it today so took in my passport and APRC to a Chunghwa store, and they spent the first 10 minutes or so insisting that foreigners could only use their passport as primary ID, meaning I’d need to enter that when buying credit and go to the hassle of updating it again in 2028 when I get a new passport.
Not a massive inconvenience of course, but I suddenly remembered this thread and @Mataiou’s NCC complaint (which I’d misremembered as against Chunghwa not Taiwan Mobile) and decided to push back a bit, just for fun. So I mentioned the complaint to the staff, showed them Article 77 of the Whatever Act, and said I’d be filing a complaint too. After some discussion between the four staff members there, it magically became possible for them to use my APRC number instead. (For some reason, they also needed to take a photo of me when I registered with my APRC, but wouldn’t have needed to if I’d used my passport. 
)
Anyway, little victories… 