With this series of photographs mostly captured with my D810 and PUFlash you'll understand better one of the reasons
I moved back from D850 to D810:
I had no access with my SB800 mounted or I would have broken it.
Contrary to many pro photographers' opinion, on a pro camera a flash like SB800-...-910 makes that combo very fragile.
PUFlash is great. Every professional camera should have one for in case....
Kindest regards,
Stany