They should come up with a freakin' guide to explain to people how to make the most out of their phones with this feature to ensure it's working. There are too many variables here like capture outside the frame, file format (Efficient or most compatible), etc.
CotF for photos is disabled by default. So the normal user (who doesn't care for camera settings) will benefit from Deep Fusion once they install iOS13.2.
But for the rest of us it's really damn confusing. iOS used to be mostly self-explanatory. Now you have to test different options to find out if a new feature works or doesn't work.
I always wonder how much Apple intends for the user to find out. By default, the outside the frame feature is turned off. Deep fusion should be the priority on all phones. I'm still unclear why I wouldn't want both. Give me both of them working together.