IMO, Mixed Mode (in any of its variouis forms) is the Devil's work!
Would you consider it "normal" to have one pilot flying one control and the other pilot flying another control during an approach?
If your answer is "No!", then I suggest that the same opinion should carry over to Mixed Mode when using automation. Having more than one pilot in charge of manipulating the controls baffles me, and that includes "George" as one of those two manipulators.
Granted, in 3-axis only aircraft, you have no choice, but to purposely do that in a fully-functional 4-axis AFCS?
Not for me, thank you.
Add to this, the actual or potential mixing of the longitudinal axis (cyclic) for both airspeed and altitude control is the Devil's finest work.
P.S. Generically, I do like the terms "3-axis" and "4-axis" since they fairly accurately describe the fundamental functions/capabilities of the AFCS. "Mixed Mode"? Not a big fan. Too indistinct, especially since there are several different brews you could be mixing.