Comment 7 for bug 969059

"Yeah obsiously, you cannot change the LightDM Settings when youre logged in as a regular user."
That's been made quite clear here & elsewhere
So a user would need to either switch to the lightdm user in a terminal & set options in gsetting or create overrirde file(s) & compile-schemas, not anything any normal user is going to do.

I will say that when the draw-grid option first appeared a user could enable/disable in gsettings
I guess that was considered inappropiate? & now is not allowed