Well, it might not be as comfortable as having a relocated AF mode button giving you full control with the wheels, but there is something that might help you, becasue you particularly mention long lenses:
Goto the CONTROLS menu and select option f19 "Lens focus function buttons". There you can select a number of functions to be allocated to the four buttons at the front barrel of your lens. I just tried it with my 500 5.6 PF and the 500 f4 G. I have set AF-C D9 as my default via AF mode button and I selected "AF-area mode --> Dynamic area AF (51 points)" for the menu option mentioned before. Now I have AF-C D9 in normal operation and as long as I hold one of the four buttons on the lens I get AF-C D51 as long as I hold the button. As soon as I release it I am bacl to D9 again. My small and my big 500 are the only lenses that have the buttons, but IMHO with shorter lenses handheld it should be possible to use the normal button anyway. It should workk with any pro grade lens from the 70-200 upwards - unless they are so small that the buttons wouldn't make sense - like with 300PF.
Oh, I fogot to mention: The switch on the lens ust be set to AF-L, in position "Memory Recall and "AF-On" function mentioned on the switch is overruling the seting of option f19.
Hope this helps a bit
Just saw that
@Thern came up with the same, so at least you know it seems to be normal for D4(S) to behave that way