For some people like me, this could be the turning point to actually start using Lemmy (few but still!). I loved Lemmy and the only thing I disliked was being unable to navigate it with a keyboard like I used to do with Reddit/RES so I created one :)
Hope this is helpful
EDIT to share the hotkeys:
Down = Next post / comment
Up = Previous post / comment
Right = Next page / parent comment
Left = Previous page / parent comment
A = Upvote
Z = Downvote
X = Expand
C = View Comments
Enter = View Link
I’d create a GitHub issue and discuss it with the developers first. As long as users can opt out it might be reasonable.
But having a lot of people use the extension in the meantime would prove the demand.