I cant answer to the upgrading, but in my case, Intuit was able to get me access to toggle the new/old template. It doesnt matter where the invoice was created....
I'm still on essentials, and somehow (maybe by my insistent pestering) I have access to the old layout again. I have other colleagues who do not have that optio...
I'm not sure how or why, but I now have the option to go back to the old layout. Perhaps you can ask intuit to do it for you too. I only was given the option on...
