Seems AMD is a little better than you thought!
Old news I know, though still interesting to see people's thoughts on why AMD were 'unable' to introduce Freesync in windowed/fullscreen windowed mode. Also proves that it isn't a feature that only the Gsync hardware module can provide.
Yep,
Might want to update your OP to add the info of Freesync now working in borderless mode as of Crimson ReLive 12.1.1