Sketchup on Mac is totally incapable to remember toolbar neither positions (SU toolbars) nor status of Plugin toolbars.
The legacy toolbars are scattered across the workspace and each and every time I boot Sketchup first thing I have to do is to search and rescue the legacy toolbars (like Shadows, Scenes, Tabs, etc).
Some Plugin toolbars however persistently appear always at the same spot I had them when I first ran the plugin. No matter how I close them, the next time I start SU the are there again.

Does anyone know how to tame this behaviour? Or for God's sake does anyone know a programmer at SketchUp who could care about this?