Make size of bars in starter roadmap reflect the estimate of the feature Merged

I am laying out a roadmap on the the starter roadmap for features which have estimates and releases which have velocity. There is no meaningful way for me to make the size of the bar reflect the size of the work to be done (other than manually doing it). This causes me frustration as I have to verify that the roadmaps I am laying out map to real resources and timelines and are not just optimisitic. Isntead, what I would like is some way to make the bar size on a roadmap be a reflection of the estimate of the feature and the velocity for the release that contains it.