That’s correct - sc compressing the air also heats it up, and the intercooler tries to bring that compressed air temp down as much as possible, increasing o2 density. If the air is warmer than expected, I assume the engine will compensate with less gas to keep the fuel mixture correct, but the net effect would be a little less power and possibly a higher running temp (not sure how much extra cooling capacity the system has via the thermostat to deal with hot intake air). I suppose that also could contribute to the pre-detonation.
Since I thought you were getting a misfire only in one cylinder, I didn’t think sc cooling would be the cause as it would affect all cylinders roughly the same. But since you are misfiring in other cylinders and both banks, then maybe that’s it.
My concern re coolant was the possibility of an air pocket in the intercooler giving a false temp reading.
Couple other possibilities just to put it out there: First, there might be a fuse and/or relay for the aux coolant pump, and corrosion in the connector might also be something to check. Second, I believe the p026A code is a discrepancy between expected compressed air temp and expected ambient intake temp, so the error could possibly be in the ambient intake temp sensor - though I’m not sure which sensor is used. I think the MAF sensors have a temp sensor component, so that’s maybe the reference temp used for the calculation.
Good luck with it. Let us know what you find.