I’ve published my first extension, Hide Back Faces. It implements back-face culling, so faces appear one-sided – they automatically hide if they face away from the camera, and you can select objects behind them.
This can be especially useful for working with interior spaces. With correct orientation of faces, as you orbit around a room you’ll be able to see inside without having to hide walls or use section planes.
It’s designed to work as seamlessly as possible – it constantly updates as you orbit around, handles groups/components correctly (not affected until you edit them), and doesn’t clutter the undo stack. You can use it just like you’d use another View mode toggle.
Here’s the warehouse link, with more instructions in the description (it’s free): Extension | SketchUp Extension Warehouse