Originally Posted by jccaclimber

I did, thank you for asking. I also don’t see any great harm in verifying what I asked. All sorts of strange things happen when you route things wrong. People sometimes provide an imperfect description as well. Frankly, anything bad enough that other people around you are asking why it hasn’t been addressed is IME diagnosable in under 30 seconds by a reasonably experienced individual, so we may need to read between the lines a bit and accept the OP as a human rather than perfect narrator.
The OP was pretty thorough in their list of already searched places, but is clearly missing something because they haven’t found the issue.
For some additional background, I’ve had someone ride into the local co-op with the description “loud in the upper gears, but not as bad in the lower ones”. The problem did turn out to be improper chain routing through the derailer. I figured it was equally loud everywhere, but the rider clearly did not.