NOTE: This suggestion is for Confluence Cloud. Using Confluence Server? See the corresponding suggestion.
Atlassian Update: December 11, 2020
Hi Confluence Cloud customers,
Thank you for your ongoing engagement and feedback on this feature request. I’m excited to announce that inline comments in edit mode is now live to 100% of customers. You can now create, view, and resolve inline comments whether you are viewing or editing a page. We hope this new feature helps you and your team collaborate more effectively in Confluence Cloud. To learn more about the new feature check out our community post here: https://community.atlassian.com/t5/Confluence-articles/Inline-comments-while-editing-FINALLY/ba-p/1444781
Product Manager, Confluence Cloud