A couple points: Shaft vs chain is like Protestant vs Catholic, Ford vs. Chevy, Mary Ann vs. Ginger. I see no profit in going down that road.
Back in the early 80's Honda mated a shaft drive to an inline four to create the big CB900 Custom. To do so they had to add a couple extra components which gave them this very cool hi-low range but a longer bike. Never rode one, but I liked the bike. Not a sales success (it was up against the GL1100 for touring and we all know how that turned out).
Finally; for what it is, the CB1100 had to be chain drive. She is a retro bike, designed for the modern world. If it had come out with a shaft drive, most of us would have said "should have been a chain drive, all the old sporty I4 Honda's were chain drive; Honda missed the mark going with a shaft".
If you make all these "improvements" to the CB1100 you now have an older design (refreshed, but dang, old hat!) up against modern bikes that have already taken advantage of years of improvements. We already have great choices to spend our money on than a throw back bike with shaft drive. I'm pretty sure the Moto Guzzi would be a better choice unless Honda could out Moto Guzzi Moto Guzzi (and I think they could very easily).
Honda could very easily design them selves right out of the niche the CB1100 sits in; ruining a very well thought out machine and shooting its' self in the foot as customers flocked away from it.