I don't want to show any number at all. One of our primary goals was to be able to single source roadmaps for multiple target audiences and very few of those need any kind of reference identifier for features that we're discussing at a largely global level.
It's just not aesthetic.
There is a lot of flexibility for the visual quality/format of the presentation, but then there is this big "engineering" feeling alphanumeric reference in the middle of my otherwise sexy roadmap.
Management and marketing are going to balk at this, and we're going to be back to manually rebuilding road map views in Powerpoint.