I'm not a fan of anything that facilitates/encourages use of the admin Plugin/Theme editor, without addressing the glaring problem with those editors: they are inherently and severely unsafe to use.

The admin Theme/Plugin editors (especially in their current state) meet an edge-use case that would deem them unfit for inclusion in core under the "80% rule" applied to most everything else - except that they scratch an itch for developers who have the decision-making power to keep them in core.