This is the current version of spec for long-form for reference. Seems like iii is the most flexible, but more work for you all of course.

“Post Approvals of replaceable events can be created in three ways: (i) by tagging the replaceable event as an e tag if moderators want to approve each individual change to the repleceable event; (ii) by tagging the replaceable event as an a tag if the moderator authorizes the replaceable event author to make changes without additional approvals and (iii) by tagging the replaceable event with both its e and a tag which empowers clients to display the original and updated versions of the event, with appropriate remarks in the UI. Since relays are instructed to delete old versions of a replaceable event, the .content of an e-approval MUST have the specific version of the event or Clients might not be able to find that version of the content anywhere.”