I fly my Tam F18F with ail, elev, rudder and it flies great that way.

I also have planned to set a mix that would allow the ability to have the elevators function as ailerons to try for regular flight but also in case I ever had a aileron flutter problem etc. Would allow roll control.

The only known (to me) problems with flutter on the F18F has been rudder or aileron..just my two cents
Dave