[mst]

On Z 50 you push the ISO button and turn on or off Auto ISO with the front dial or select (and override at the same time, if AutoISO is active) the ISO value with the rear dial. I fail to see a big difference? Especially the override bit is new to me, I can't do that on Z 7/6

Thanks for this find... I honestly simply missed this feature in the manual. So, can we agree that the Auto-ISO with the Z50 is not as bad as I thought, while the implementation in the X-T30 it's more flexible than in your X-T2?

On rare occasions I DON'T use AutoISO, such as studio works, architecture and landscape - everywhere else AutoISO is active as I do not care much about noise but do care about aperture and shutter speed. Noise is hardly an element of composition, at least in most pictures - the other parameters are.

Well, of course shutter speed and aperture are the main tools, same here. I do however prefer to stay as low as possible with ISO and then set aperture (usually) or shutter speed (only when the subject requires) accordingly.