Hi Chris! This feature would be awesome! There are more than several posts scattered around the Community that touch on this. Manual audit of Dashboard Permissions is NOT fun - Copy and Paste can only do so much. Haha But yes, +1 to this request!
Right now it's copy and pasting the the name of the reports and then clicking on each one and copying over the user list. Then cleaning that up. It did make it easier when User Groups came out though - so we don't have to grant access individually to our users. But still a time consuming none the less.