Preserve focus on page-backward
Say one is on a page, click on a link or tab to a link and press enter. This browse to a new page. Then if the user press Alt‑Left to go backward, the focus is lost.
Preserving the focus would adds two values, even for mouse users:
for both mouse and keyboard users, it would show which link was
clicked (which is not the same as showing visited links)
for keyboard users, it can save a lot of tabbing to get to
the previous or next link (in tab order) and/or simply help
avoid reaching the mouse (which may not be available or which
may hurt in some way).
In any case, this would not cost anything to people for which it would not value anything.
I'm introducing this proposal for after a page-backward, while this probably would be as much worth with going back to a page with alt-right (the other way).