I've not tuned an ECU with knock detection (but I have tweaked the one adjustment pot on a standalone KnockSense box), so these comments are just a guess. Your setup and voltages seem reasonable: voltages up to a volt, ~6kHz center frequency, gain of 2, and a small integration window to get a bigger signal.
If you look in the Volvo 31397-1 Ignition Greenbook, it talks some about EZK-116 knock detection. It mentions a 7.5KHz center frequency, which is a bit on the large side for a 96mm bore and traditional resonance mode equations. It also says EZK uses a window of -15 btdc to +55 atdc, which seems a big big.
Have you checked that your knock sensor mounting boss and sensor bottom are smooth (no corrosion), and that it's torqued properly?
gross polluter on here worked a lot with the MS3 knock detection during development. The MS3 detection is similar to AEM, but looks like it's not as advanced for responding to knock once detected.