At 80mph on a Touring you are probably turning 3150 +/- 150 RPM in 5th. It isn't an issue to cruise at 80+ all day long. Yes, a 6th gear would be nice but it isn't really necessary on this bike.
When I am going home every night I have to take an exit off of the freeway, I approach at 75-80, clutch in, down two gears and use engine braking and then throttle to maintain appx 60mph through the first curve and by then it is downshifting/coasting/gentle braking to the stop sign.
My exit: The Interstate is on the right of the pic, Stop sign at end of second little curve.
I don't chug on purpose, ever.
bob