As of H1 2020, to get the Fiori based achievements/activities view, you need to turn on new features from the Admin Center. But if you turn on new features, you lose feedback until H2 2020 when they release it back out again. Currently, it's one or the other.
New view: Feedback is not available
Old view: Feedback tab is available
2. Turn on/ off new features: Admin center -> Continuous Performance management
4. Appropriate RBP for feedback view in the organization
The visibility of the feedback is based on the RBP for the "permission to read feedback on achievement".
This permission is granted to the manager role; the feedback is only visible to the manager so the manager can see his direct report feedback only but cannot search for any other users.
5. Reporting capability
Ad hoc reporting can be created on the feedback functionality.
6. System token
[[FEEDBACK_REQUEST_LINK]] token is used in the email subject line. The link directs to the Provide Feedback (CPM) tile on the Home page, and not the Continuous Performance Management.
7. Request feedback on Achievements link-unlink
As of b1711, Continuous Feedback replaced the legacy "request feedback on Achievements" feature. It will still allow you to request feedback on the Achievement and link that feedback to the Achievement. But if you need to delete the achievement, the feedback simply reverts back to being unlinked.