The ministry of education has finished their suggestion list for 300 commonly used Holo Taiwanese words for which a character is hard to pin point. It also comes with a handbook of use and complements the official Holo Taiwanese romanization system. In general, the new suggest list also is in line with the newly passed Langauge Development Law.
I suggest looking through the first link and seeing what you think of the list. ALso check out this badass dictionary.