@BetterRed While looking at why my Calibre didn't have that long-press affordance at the place you mention, I found that I was running an ancient version of Calibre - 1.48, which seems to be the last .deb-packaged version of Calibre on any Linux repositories! I had assumed my regular 'apt-get upgrade's would have taken care of keeping Calibre updated, never knew that method had been abandoned. I'm now downloading the latest version through the
recommended Linux install method.
And what you mentioned certainly a nice-to-have feature, but probably takes the same amount of time as manually copy-pasting it using keyboard shortcuts takes for me. But I'll give it a whirl once I get the new Calibre set-up with my preferences. (Don't want to just copy the config directory between major version changes, since that's already unsupported and might mess things up.)