Hi all developers!
After thinking about doing it for several years I've finally gotten around to clean up the old and dirty code in my solid tools to a state where I can open source it. This project was actually started not with the intention to be a standalone plugin, but because I needed sensible solid operators for another plugin. I have used it in several plugins since and thought more people might find it useful.
There are several differences from the native solid tools. My version modifies the existing group/component instead of creating a new one. It also honors the existing materials on both group/containers and on individual faces instead of painting individual faces with the container's material. Both these properties makes it really useful in custom plugins because it behaves much more consistently to SketchUp than the native solid tools.
I'm really happy with the UX; several people have commented in the Extension Warehouse and said it's easier to use that the native solid tools. However I'm not really an algorithm person so it would be really fun if someone here wanted to optimize and improve stability.