Well actually i can not understand what you are saying?are you talking about the trampoline flexibility,i have round trampoline at my home and its much safe and there is no problem in that but its really necessary to know when you purchase it,just take it from good company so that there should be good quality of that.
Trampoline helps for tumbling flexibility,
do more practice on Trampolines , it will helps you.
Other people asked questions on various topics, and are still waiting for answer. Would be great if you can take a sec and answer them