Well LG just did not build the required functions into the firmware - maybe there is some hw support necessary as well.
ECC is (often? always?) not done by fw/software, but by hardware - afaik it involves long register bit shifting with feedback & it would be hard for even a fast cpu to do that with 22MB/sec (like you have at 16x speed).
Probably those drives which can report PIE/PIF have a kind of error counter coupled to the ECC hw which can be read. If LG spared the hw to read those registers/counters, no chance for error testing.
While this may sound sad, I have to say the scans of LG burns I did with my BenQ were really good, so probably LG just decided to make a good flawless everyday burner for people who are interested in saving data to DVD and not in error tests.
Maybe just get a really bad/old DVD-ROM drive and make the transfer rate test with that one, as suggested above. If a crap drive reads the disc ok, assume it to be good. I already had scans which were great but my crappy Tosh SD-C2402 laptop drive didnt read them. And I had worse scans it would happily read. So dont care too much about that scanning.