Yes, ctrl-F7 (de-)activates keyboard navigation. When activated, the problem of grand parent does not exist. I don’t use a mouse or touch pad normally.
I think the point was "holding tab to cycle through every user interface element until you get to the visual tabs on the page is an exercise in frustration."
Also for anyone trying to turn on all-element keyboard navigation, you'll probably need to use ctrl-fn-f7.
