I see what ur all saying, the extra friction/drag caused by belt tensioner is minimal miss the apex by a foot and u have the equivalent probably! In regards to power loss again minimal we loose more from having the rear toe uneven one side on the 3 degrees mark the other just on the outside of the mark.
Using the tensioner for belt tension is fine IMHO, but lets be frank the diff height position can u actually feel the difference from diff low to diff middle so to speak? I can feel a very very slight change from diff high to low but it is tiny and against the clock no change.
Not sure if everyone knows but u can have less teeth on a belt and nothing changes, there is just less belt! The internal ratio stays the same.
J