As a Dynamics CRM User who supports D365 CRM IT projects and enhancements it is extermely painful to validate specific end user experience when implementing net new features. It would be helpful to impersonate a specific user in a sandbox environement to help validate that the new functionality is working as expected. Otherwise we don't truly know if a feauture is working as expected until end user UAT. Creating dummy generic user profiles has several limitations and require a high level of support from our dynamics admin
In addition enabling impersonate would be helpful for triaging system regressions for specific CRM users. Today we have to meet with the end user to see what their issue is.
We have impersonate native in our SN platform. Not having impersonate is viewed as a major setback for Sales Operations as we as for IT support as part of our migration to D365.