This suggestion looks great, but I think it should be added to the scene window and the context menu in Layout.
Maybe there will be some standards Shortcodes will be defined which will be display only if the file would be opened in older versions of SketchUp, these images explain the idea:
The new versions of SketchUp:
The old versions of SketchUp:
And could be added to the layer window as well:
The new versions of SketchUp:
The old versions of SketchUp:
I think that will take SketchUp to a new level of organization and convention workflow.
If anyone have a better suggestion please share it with us.
Best,
Mousa Abu Doush