The answer to that is, as usual with these things, it depends on what you are doing. If the F2 doesn't support the L3 feature you need, then you have to proxy it to the M card, so it's totally dependent on what features are in use. I don't know if the F2 card will do VxLAN , OTV, you can use the cisco feature navigator to check and see what they will do, or look at some of the Breakout session documents, or open a ticket with Cisco. I find most of the info from the breakout docs or ciscolive.
Function of M line card with F line card is the F card will proxy route it to the M card to use the features (of course this is a performance hit)
This video maybe can explain some: https://www.youtube.com/watch?v=GOYUCBrUtfE
