I came across a possible issue for your users. When a theme is duplicated, it keeps the original name. I duplicated the Responsive theme and forgot to rename it to something different (i think).
So, i noticed today that Responsive had an update and both themes, the parent and child themes were asking for an update. After i changed the child theme's name, the update request disappeared.
Maybe there should be a failsafe of sorts if the name is the same? Maybe there is already?
I would hate to accidentally update a child theme!