Just use a PURPOSE built aerobatic machine and be done with it, one that is designed to do aerobatics, instead of trying to do manoevres of sorts in slightly semi-aerobatic machines.
Makes you wonder, when you hire out ZK-XXX, a 172N from somewhere, just what it has been through during it's 25 year life....I shudder just thinking about it.
I'll stick to purpose built aero machines thanks very much.