There can be a difference between elastic doughs. Different people use the terms extensibility and elasticity different. I think the term extensible means the character of the dough is that it allows stretching without springing back, and the term elastic means the character of the dough causes it to spring back. This also can be called memory. If you are having problems with your Luigiís dough balls in opening them, they could be something wrong with your mixing process, how the dough ferments, or other things. There are many variables that can go into each formula.
This video by Tony Gemignani does show the pizza dough fundamentals of opening a pizza dough ball.
If you try another experimental Luigiís dough, try to record the final dough temperature, how long the dough was mixed, (what were the mixing methods, type of mixer, or mixing by hand) how the dough balls looked before and after fermenting, and notes on how you opened the dough balls and how they performed. They are many variables in the process, so maybe if you keep notes on your whole process either I or someone else can help your better.
It is good after you get your dough okay you can use a friends deck oven and Hobart mixer. I had my oven about 525 degrees F, but I would have like to have it a little higher, but since I made my other pizzas at about 525 degrees F, I canít just up the temperature of the deck oven for one pie. Each deck oven operates different, and there might be experiments to do in each type of deck oven.
You can use whatever hydration you feel might be okay. You might stay in the same hydrations you were trying to see what happens first, then go to another hydration if things donít work out well for you. You said the Power Flour didn't have any problems with mixing with the hydration you were using, if I remember correctly.