No visible difference between regular and inverted faces (toggle suggestion?)

[vulture-boy]

Having an issue where I somehow accidentally made an object entirely of inverted normals and didn't notice until I imported the object into Unity, so when the object is rendered I only see the backsides of the tiles.

Any chance we could have a toggleable visibility option that applies some sort of highlight (e.g. like the selection highlight) on tiles that are inverted for the currently selected object? It would be really helpful for troubleshooting.