I actually use the "Letter to the CEO" form on Rugers site. I complained a while back about looking at 22 revolvers and there being a few cheap ten shots available but no decent ones. Why couldn't Ruger make one. When They did I asked why they didn't make it convertible, even if it could only hold a few less rounds.
I'm probably selling my single-six convertible for a single ten at some point. If the single nine was convertible I would be interested. Can't be too hard to make an aftermarket cylinder though.