I had flown for CAL, so I can tell you that the Taiwanese ATP Lisence is going to be good for transferring the TR depending on the receiving Aviation Authority.
I have an FAA ATPL Lisence and I could transfer the B744 SIC from the Taiwanese ATPL at the FSDO in Anchorage.
You should have to make an appointment and complete a form. As far as I remember the minimum requirements were 500 hrs SIC and a signature from a company TRE.
I tried to do the same in Spain...but it didn't work, but many of my colleagues from Swiss and Portugal did it.
So If you hold an ICAO license you should try to keep it update until the moment you bail out from Taiwan...