Without Turkey being a FULL member of the EU, which I seriously wonder why it would ever want to be, a "Federal" based Cyprus solution is a Major risk for both the "Turkish Cypriot" and "Greek Cypriot" people, both legally, politically and geographically too, but for different reasons!
Cyprus is best kept as a Two Republic state Confederation, where it's just the Greek Cypriot side whom are finding it hard to accept. With a little land give-and-take, a Two Republic stat formula would be amazingly successful and pragmatic, But, of course, our paid off Turkish Cypriot leaders (apart from Mr Ozersay) do not show any signs of realism or bravado when it comes to the Cyprus question and the historical (from 1571) protection of the rights of the Turkish Cypriot people of the TRNC.
In particular, Turkey amazingly plays the Cyprus question like a Pawn in a Chess game, only to dismiss all pieces before the real game even takes off - and I am talking about the Greek Cypriots being the Pawn here first. You constantly fall under Turkey's mastery every time. Do you know why? Because, deep down, you are Ultra-Hellenic Nationalists and can never perceive the Turkish Cypriots as being masters of their own Internationally recognised Republic state, and Turkey plays on that with you and then WINS - every time (like how it will win again, where the cracks are already starting to show!). Hence, why the Cyprus problem hasn't been solved since the signing of 1979 - "High Level Agreements" when Makarios was tricked into agreeing to a "Federal based Bi-Communal, Bi-Zonal agreement".