It looks to me like going to home page and adding a new block in the end is the most common action in Logseq which should deserve a shortcut. Currently I need to press down arrow multiple times in order to go to the last block and then press Enter two times to add a new block.
It’s not that easy and intuitive even using mouse. Maybe it would be good to have Enter to add a new block when page is unfocused, which currently does nothing, or have a common key for both focused and unfocused modes, maybe Cmd-Shift-Enter.