Coming from mixing shimano cassette, chains, Cannondale cranks with Sram 22 I didn't realise how picky the 12 speed systems are with matching chainrings and chains.
Sorry I realise I didn't mention that I was referring to the road side, with Dura Ace and Ultegra going 12 speed recently and it all fitting on standard 11 speed hub bodies.
This popped up for sale locally for a lot of $$$