I moved it from bug reports to feature requests and updated the title; feel free to adjust.
The observation detail page isn’t optimized for speed IDing/annotating; I’d suggest using the Identify page for quicker workflows. I tend to have identifying sessions vs. annotating sessions, though some (including you :) have suggested improvements for quicker annotating while identifying.
https://forum.inaturalist.org/t/turn-annotations-section-into-a-table-with-check-boxes/10967
https://forum.inaturalist.org/t/optimize-the-user-interface-for-annotating/7662/3
https://forum.inaturalist.org/t/add-keyboard-shortcuts-for-annotations-in-identify-mode/6276