I've gone the other way, at least I think it's bass ackwards from what most others do.
I've set the back 'AF On' button on my 6D to "Af Off".
I have only two lenses, 40 shorty and 24 - 105.
The focusing ring on the zoom responds as I expected, any time I grab that ring, I'm in control of focus.
The 40 doesn't do that at all, for me to have manual control, I have to switch to manual control.
Now, with back button 'Af Off", anytime I press the Af On button, I am now in control of focus, I can leave focus where the camera/lens set it, or fine tune as I like. If I want to return focus control to the camera/lens, I release the Af On/Off button.
If I hand the camera to someone else, all is normal for them.
I generally shoot in manual, f6.3, 125th, auto ISO. I've set the 'Set" button to ISO so I can quickly control that as desired though I cannot return to Auto ISO using the Set button.