This would be useful to get on other cameras as well. On the D6 you can move the release mode from the dial to a button on the lower back panel (multiple frame icon) but pressing this button and using a dial to select the mode is still very slow. If one could move it completely to the right hand side, or assign it to recall shooting functions would be very useful. It's just software as demonstrated by the fact that there are already two options on how to access this setting (but neither is convenient if the left hand is supporting the lens). I sent a request for this to Nikon but they seemed to think it's a good way to get me to buy the Z9 rather than give it as a firmware update on my current cameras. ;-)
I fully agree that recall shooting options should be extended on the D6 and dispersed to other Cameras. I have bought the Z9 already so NIkon does not need to get me there - nevertheless I want to continue the use of other cameras. D6s multiple frame icon on the pack appears to be a legacy of the first Z series. Z9 has this solved better - there is everyhting on the dialling wheel. Z6 only offers release mode on this misplaced button on the right bottom of its backside. If it was the idea to make it fast accessible with one hand then this failed. Worse if you press the button you do have to dial the back wheel to change settings, not the front wheel and you cant change that. No place in the menu (thus not in individual menu as well), no option to access it with a function button, no way to set it by using the misconcepted U1-U3 dials. (just info -menu) That could be saved by firmware update. I am happy with the Z9 but i want a second set of recall shooting options back and a direct way to assign spot-metering to a butten and not
Info-Menu is not too attractive for me - may it be release mode or metering mode, it is slow, and Individual menu would do that If i could assign anything there.
There is a significant number of things getting worse, features that have proven valuable and but disappeared and could/should be easily restored in the newer cameras.
And it would be advantageous to get updates for older cameras as well. Z6, D850, D500 were made capable of using CF-Express cards, D4s would deserve that as well, then one could skip XQD cards completely and standardize the card types use.
P..S. Yes I also think that designing an Adapter that supports screwdriver -AF is a complex undertaking. I trust that Nikon could solve that without issues if they wanred to.