I didn't previously know that there were any 8 ROMs that had the knock multiplier vs. rpm table like this. I thought only the 9s had this table while the 8s used the three separate values for low, mid and high.

Having this same issue with my tephra flash.

Hi VRP

I was able to sort this out.
first thing i would do is pull at least 5 deg of timing out of the whole Hi ignition map. once you have done this drive around and see if knock is still present. if you are increase the knock filter by only 1 point at the load you are seeing the knock and test again.

also you need to make sure that you fuel map is good and i would do this on a low boost setting too.

i was also able to make some DIY det cans to listen for real knock.