To my mind (and no doubt probably wrong) "Maximum range at current speed" & "Range to course end" are different questions.
'Max Range..' is probably the range following Great Circle navigation, ie. in a straight line across the surface of a sphere.
'Range to course end', seems to be exactly that. Distance to go before you reach the end of your course tracks - no matter what bizarre course changes that might involve.
cheers
Paul
__________________
|