Hi Chris,
We don't have the facility to estimate the potential space savings if dedupe were to be run on a volume in Ops Manager 3.8. We have this feature in our road map. Please get back to our product management for more on this.
But with Ops Manager 3.8 we are providing reports for dedupe space savings per volume basis/per aggregate basis and group level also.
We are providing a comprehensive graphical representation of space savings as an effect of dedupe run in the next release of Provisioning Manager which will go with DFM 3.8 release. We will encourage you to use the Provisioning Manager to see the effective dedupe space savings in details. Provisioning Manager will support on-demand dedupe run and scheduled dedupe run also.
Thanks
Tanmoy