It is very anoying trying to add grids on children frames because all grids even on separated frames appear with no reason. It has been imposible for me implementing grids since the las update. I have tried using groups but still not work.
It is impossible to turn off a parent grid and still see a child grid. Turning off the visibility on the parent also turns off the visibility of the child – so you can’t turn them off manually. So no way to view just a child grid alone within a layout.
I also agree that being able to view just a child grid would be super helpful to do more complex layouts.