Originally posted by Mikesul That makes sense. But it does not seem to work in TAV which is also a kind of Auto ISO.
If we look at the instruction 17 on page 11 of the manual, it discusses setting auto ISO with the green button. When auto ISO is enabled this does allow adjustment of the functions discussed in my original query. Adjusting the ISO again returns it again to the manual mode. As in the past I have only used manual ISO settings, with Tav being my primary floating ISO mode. Hence the functions discussed have always been greyed-out. Hopefully the mystery is solved.
Update - I have been the above auto ISO procedure for a range of modes and my findings are below:
Sv - no change to e-dial operation
Tv - Rear e-dial changes ISO and aperture
Av - Rear e-dial changes ISO and aperture
Tav - No change in e-dial operation
M - Rear e-dial changes ISO and shutter speed - aperture remains static
B - Rear wheel changes ISO only