Loosening the tension was a big plus. It was simply too tight. It was making noise no matter where it fell!
The rear sprocket is not making the noise but now the bevel box is the one. I have also noted that with the tension being loosened the bevel box whine is almost gone! On mine it wasn't much to begin with.
Now that's an interesting observation, Mike..
"If" the belt is too tight in the specs maybe that contributes to the whining on others, too? I can't see something as simple as this not being tried already by the factory, though. It would certainly not help bearing life on that side.