Simple little change: Remove tiny shadow behind new artboard
I've noticed this for years... whenever I create a new document in Illustrator--no matter the size or mode and without any bleed settings, the artboard has a tiny grey "drop shadow" behind the artboard. See ATTACHED. It does not affect art and never prints, but more times than I can count I've found myself zooming in and attempting to select/delete it, thinking I left some sort of unwanted element behind while I was working. Or I see the faint "border" and think my graphic elements aren't fully aligned to the page edge, when the actually are.
It is the only thing basically that tells an artboard from a shape.
Do not remove it. Make it more prominent.
Even better — add a variable in the Prefs file for users to control it.
Some will set 0px, some 5px.