Mobile UI: Is it possible to use calculated ratings for overall rating when section items are not ra

Summary

Using only section ratings, along with displaying items without rating them, I would like to average them into an overall summary rating.

Content

My client would like to use manual section ratings and average them into an overall summary rating. However, they also want items to be displayed so they can be commented upon.

Every time I try to set up calculated ratings in the overall summary section, it tells me that I must also use calculated ratings in one of the goals / competencies sections. In order to do this, I would have to enable item ratings, which is something that I do not want to do. Has anyone tried this set up before, and is this even possible?