Perhaps a warning box (which can be disabled) when one updates a scene SketchUp knows is used in Layout.
Or perhaps merely a warning to confirm the update in case the scene is used in Layout.
Or perhaps a warning generated by a user activated checkbox for those scenes that one has selected for use in in Layout
Yes I did this and it messed up my Layout drawing. It is fixable (undo in SketchUp), if you catch it right away. If you go too far, you end up undoing more than you want. And if you saved the model, it is quite painful.
It is hard to idiot proof (ha) SketchUp, but warnings about actions that really mess up the interface to Layout would help.
SketchUp and the SKP file do not know what scenes are used for LayOut. It works the other way 'round.
It’s the .layout file that embeds a copy of the SKP file inside it, and holds a reference to this copy. Within the LayOut document the SketchUp Model viewports have a property that is set to use one of the referenced model’s scenes.
LayOut does not yet have a “live” API, but when it does, it is likely that someone will write up an extension to test whether the model references need updating.
It is possible a non-live extension could be written that runs from within SketchUp today. That would open the layout archive and check the embedded SKP file’s modified time with that of the open file in SketchUp.
The extension may need to save some attribute data in the model to link it to a certain LayOut file.
What specifically did you do to a scene in SketchUp that messed up your LayOut viewport ?