Follow-up from "Adds todo notification for self-managed enabling duo core features"

In !189490 (merged), a number of follow-up points were raised for handling code refactoring into EE and other improvements.

• - !189490 (comment 2478207357)
  • !190853 (merged)
• - !189490 (comment 2478207380)
  • !190854 (merged)
• - !189490 (comment 2478207401) (this might require it's own follow-up?)
• - !189490 (comment 2478207413) (related to ☝️)
• - !189490 (comment 2478207490)
  • !193060 (merged)
• - !189490 (comment 2478207502)
  • !190854 (merged)
• - !189490 (comment 2478207335)