all they need to do is to implement a function to allow you to see comments section of a PDF. At least this is where I see the scribbles placed in a PDF after they are merged.
A dialogue box will add one more step. Just a simple separate icon is OK.
No, exporting just the scribbled pages is not all of us want. I, for one, don't what to lose the context of the information that I selected by scribbling