I notice when the grid is enabled it is visible to the public, shouldn't it be hidden?
This is entirely dependent on your own theme settings. On the same page where you enable or disable it, you specify which user roles see it.
There's only the one setting to turn on/off so it's visible to the public. Something like this should only be visible to the admin or one working on the theme. It doesn't make any sense to have visitors see it. I have it disabled for now.
Aren't the controls in a block? Couldn't you just disable the grid as default and enable the grid controls for your admin user?
You need to disable it. Go to your theme settings >Debugging > Roles that may use the grid overlay and debugging blocks. and uncheck anonymous user. Save your settings and voilá.
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