> From my point of view, Ctrl+R is a more portable shortcut than F5 because it is available on virtually all platforms
Both may be implemented, and F5 may be ignored in the help, just to make the shortcut working for former users of browsers supporting it.
> Windows-centric
It's supported by Firefox for Linux, Epiphany, Chromium for Linux...
> From my point of view, Ctrl+R is a more portable shortcut than F5 because it is available on virtually all platforms
Both may be implemented, and F5 may be ignored in the help, just to make the shortcut working for former users of browsers supporting it.
> Windows-centric
It's supported by Firefox for Linux, Epiphany, Chromium for Linux...