Personally, I think there is little advantage to mixing Cf into a Ti frame.
One, you're taking away one of the advantages of the Ti frame by reducing its durability. CF is a bit more subject to damage than Ti, particularly abrasion, and crash damage. It's not like the CF is going to spontaneously fail, but odds are in the long term it will not as durable as an all Ti frame.
Two, it creates another bonding issue from the CF to Ti that can fail. Again not a big issue, but an uneeded complexity.
IMHO, the whole idea was more about marketing. It came along when Ti builders were trying to compete against CF. I doubt there is any ride characteristic that you can get with CF stays that you can't get with all Ti.
__________________
You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.