Adding handlers for port B and C that just returns a simple running call counter that eventually toggles the bits the code is looking for I get a slightly different response:
H4 is never enabled in PGCR and in fact the code just jumps in and uses the PIT as is. I did implement and H4/H2 code but it never executed as they were disabled. But I have also added reset callout for H4 and when chaninging PBCR so you may get some calls to your callbacks now.
Will take a look at TIN now, I saw that the test starts polls bit #2 at Port C in port mode, just to see if there is a clock at all I would assume.