My point is that if my preferences are set to “Open all external links in a new tab”, I would expect that to be honoured whether I click the link with the mouse or press Enter on a keyboard.
Yes, I can use Ctrl + Enter to open a link in a new tab, just as I can use right-click or middle click to open a link in a new tab with a mouse. But with my preferences set as they are, that shouldn’t be necessary.