Add Feature: restrict DEBUG_ON to developer logged in

I am only suggesting an added feature:
Switch the debug on only for users that are logged in (maybe by capability: editors, admins, …).
I review my websites periodically and always go to the backend to check plugin/theme versions, etc… I like to run thru some frontend pages as well.
This way we never have to worry about the public seeing warnings & notices when we are debugging stuff or worse – forget to turn it off.

Thanks for your consideration.