[jank]

This si all true when one considers an "ideal lens".
The coc may also get defined -enlarged by the resolution of the lens , not byt the resolution of the sensor/ film only.
That would be also true for the size of the apreture, the lens when stopped down also looses its performance, therefore apparent depth of field increases.
The older , poorer lens might exhibit, or rather make impression having larger depth of field.
Jan