Highlight the active artboard MORE
When we work on multiple artboards, it will be good to recognize the artboard who is used when I select a object or I click on a artboard and to active it.
So when I select all elements in my document, with the keyboard shorcut, all of the objects of my active artboard will be selected. Or if I select an object every where, the artboard containing this object will be activated automatically.
often, i select all objects on my first arboard but he's not active and when I paste in place in an other artboard of an other document, he's not placed at the good place !!! I must double click on the artboard to be sure that he's active.
Relates to https://illustrator.uservoice.com/forums/333657/suggestions/38253112
(Changing artboard frame colour)
This should be re-addrressed, I agree. Slight darkening of the artboard's edge is not enough to notice.