Jeff, A slightly different angle on your question but covers much of the same info in this thread. https://www.nikoncafe.com/vforums/showthread.php?t=180193
I did some very detailed tests on this issue. In my opinion, it doesn't matter, and you might as well save the space. You have to push so many things so hard to see any difference at all that it's almost absurd. No reasonably-well exposed photo, undergoing reasonable manipulations, will benefit from 14 bits once printed. Cheers.