I've tried editing a number of posts, new and old, varying from 5 mins to 12 hours after the edit, and it says "edited 12 hours ago by admin" with the word edited in black. No link.
I've checked and double checked the few config options - trying to change 5 mins to 30 seconds with no joy. I've even changed the Visible option to allow ALL to see edits. No joy.
I'm on q2a v1.7.