First, you have DEX in your trans?
Secondly, how can you monitor KR to determine if it'* a knock sensor if the knock sensors are disconnected?
I would try to isolate this to the front or rear bank first. By disconnecting one at a time. See if it'* a front or rear issue and go from there. I suggested this to Boosty a couple times as a possible troubleshooting step to narrow it down.
I wouldn't rule out the trans as a possible source of false knock. Have you considered the false knock kit?
What about your lack of EGR? You could still have a combustion temp issue. Not much you can do about it now, considering how well your SC EGR stovepipe is blocked.
But an EGT gauge may be an interesting thing to look into.