I doubt mixing materials would negatively affect handling at all. What I would be concerned about is how the bonding of the dissimilar materials will hold up over time.

The coefficient of expansion difference (with temperature changes) between the two materials may be significant enough to have an effect on the strength of the bond between the Ti lugs and the CFRP tubes depending on whether it's purely adhesive or is both mechanically and chemically bonded. This has been a problem on some early frames using CFRP tubes and aluminum lugs as the frames have aged.