Hi Karl,
I would suggest you to use the functionality of Authorization Groups and User Status & Activity Control in REFX.
1. REFX-->General Settings for Master Data & Contract-->Authorizations-->Define Authorization Groups.
2. REFX-->General Settings for Master Data & Contract-->User Status-->User Status & Activity Control.
Try these options and see if it helps or if more clarification is required please explain your scenario in more detail.
Regards:)