Its a fallacy that the 40 sizers need a 46 or 55ax. A colleague at the field is flying a 40 size 60" span trainer with a 35 size 2c and it can do all the aerobatics that a trainer can do and more. You just need to prepare a bit earlier (give throttle earlier) so you have airspeed to finish the move. Limited to just sports flying of course. If you want 3D, some will say even a 75 will not be enough (airplane being suitable ofcourse)

Ameyam