I think boils down do "main-thread keyboard scrolling code needs to scroll the visual viewport". (Marking as blocking desktop-zoom-nightly for triage purposes only, I'm not necessarily arguing that it needs to block nightly.)
Bug 1656689 Comment 2 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
I think this boils down do "main-thread keyboard scrolling code needs to scroll the visual viewport". (Marking as blocking desktop-zoom-nightly for triage purposes only, I'm not necessarily arguing that it needs to block nightly.)