Manufacturing variance against a different revision

Couple of questions here based on one problem:

I’m looking for a way of getting better visibility of manufacturing variance when a job closes. Ideally if it is possible Per Operation and Material. At the Moment it lumps it together and although I can get the results outside of the system it would be nice for Epicor to do this.

The Second bit is that I want the variance to be Calculated against a fixed Revision BOM for the part. (A = costed Revision) that may or may not be used on the BOM.
ie Part ABC has Revision A (Costed) Revision B and Revision C
What I would like to acheive is If Job 123 uses Revision B the Variance is calculated against Revision A no matter how different the routing is. Also if job BOM changes are made to the revision on that job they also get calculated against Revision A.

Does this make sense? We currently want to fix these standards on the Revision A and currently some plants use different revisions to achieve the same result. this may because of Workload, Machinery downtime etc.