That's not a bad idea. That's what I did with my standard. The bike is geared a little too low as it is. Cruising in 5th at 70 or above, the bike could certainly use a 6th gear. I'm really surprised they didn't build it with a 6th. It seems most everyone else is using 6 speeds and sometimes as a 2nd overdrive. We all know we could use the improved fuel economy. I thought my standard was bad but, I think it gets better than the Tourer.
I'm not a fan of 6 speeds. With as much torque on tap, Triumph could have easily made the Rocket as a 4 speed with a 5th gear as an overdrive. just my 2c.