I don't have much to add other than my 07 hemi pickup had a bad abs hub sensor that didn't throw codes, but caused other issues. One recommended to remedy My cruise not working was to replace the brake light switch, so you could be onto something there. Ultimately I changed it with no results, then found my abs sensor.
I recall certain year ecu's being problematic for swaps, but since I only deal with new, and don't ever get into takeouts or repurposed/modified harness's I don't have much info on that. Just wanted to share we got 4 aftermarket pedals as samples, and only 2 worked. Bought the Chrysler oem ones, and no problems. The factory pedal was oddly cheap. Maybe $50? You might want to throw a new one at it if your testers have all been takeout, especially from different year models? Good luck!!
