It would be great if it was. 
By selection by area, I mean the functionality for moving, resizing, duplicating and erasing notes.
Hello, do you mean “Selection by area” is available between different pages?
In that view were half of the screen is a PDF for example, and on the other half you take notes, the “selection by area” is not available, on the notes side. It could be available, as it is the notes app.
I got it now. We will forward the request to add the “Selection by area” on sidenote mode to our relative colleagues to follow up.