Ahhhh......If you can fly the pattern with an LT-40 inverted...you can fly anything inverted......I praticed and praticed catching my LT-40 inverted.....finally got where I could do it at will.....as I was doing this, worked on turning inverted.....until I could fly the whole pattern inverted.....why do it with a trainer? Because it is hard....what is a trainer but an airplane you learn with.....
Did it help me who knows but my second airplane was a 4 Star 60....one fine day I was inverted at the departure end of the runway at around 25 ft altitude...no warning dead stick...no problem got the airplane down and stopped it at my feet...no I didn't fly the complete pattern...and had light winds.......but being inverted dead stick while it got my attention wasn't that big a deal.....
To answer your orginal question. No you haven't mastered your trainer.......Good luck and Good flying