It’s common to bust published minimums going into those islands. You simply build your own VNAV/LNAV approach and fly Pacific IFR (I Follow Reef). Perhaps this crew wasn’t as familiar with Pacific IFR procedures.
Air Niugini crews are very professional and very familiar with Pacific weather, and they don't "build" their own procedures. 45 years of safe operations in a very demanding environment is testament to that.
What is commonly misunderstood about Chuuk (and several other Pacific destinations) is that it is a
cloud break procedure; although a 3 degree profile is published, it takes you to the MDA at the MAP. From this point you either need to fly level (if visual) to acquire the PAPI or follow the missed approach procedure (if not visual). Simply continuing to descend on the same profile (even if visual) is not an option.
I don't have the IT skills to post the GPS or NDB approaches to 04 here, but I'm sure someone does.