OK, pedigree resolved - this RT was built in January of '09. The production foreman's name is... aren't VIN websites wonderful?
The reason why there seemed to be no difference in the settings other than sport is... wait for it... here it comes... almost here... and... The rider didn't RTFM. The suspension setting can't be changed on the fly. Stopped and changed, comfortable is... comfortable. Not cushy, just comfortable. Normal is a little firmer, and sports is "lose some fillings". Dunno why the PO didn't get ASC with ESA, but he didn't.
I've spent some time chasing the bike a bit harder through mostly near-twisties (curves, moderately tight, but not
that tight) and a very few stacked 90° corners (left then right or vice versa). I guess sport feels a little more assertive, if not aggressive. Comfortable doesn't render the RT unable to round short radius turns. No doubt a pro could easily show me the errors of my ways.
I spent some time fiddling with the seat (v. nice to have a manual for the bike!) and found it's as low (in a relative sense) as it's ever going to get. Why this bike is so tall still escapes me.

The funny thing is that the more I ride the bike, the more I like it. What saves me from a serious dustup with SWMBO over a bike change is a) no water cooling and b) I still hope Publishers Clearing House will send their Prize Patrol, with a sizable delivery, to our front door. a) Find a different bike or don't get stuck in traffic in the summer. b) Penguins hope they can fly.