I should clarify my earlier question.
Have anyone ever grafted an American Persimmon (like Prok) and an Asian variety (like Tam Kam) onto a single tree/rootstock)? Growth rate maybe different and cause imbalance/problem later on, maybe?
If this work, then if the less hardy one died out in a harsh winter, at least the hardier American Persimmon variety would be able to provide some branches to re-graft another Asian Persimmon onto? This idea I picked up from the conversation with TonyOmaha, the die-hard persimmon zone pusher...
What's your take regarding this subject? Of course, if someone with a strong background for persimmon like you had already tried and not worked out, then we should not spend years to find out the answer that was already provided!
I have zero experience in persimmon so I'm still trying to pick up info here!