Currently, Sidecar slides in from the left within the window you are on. It appears in a layer on top of the contents of the window - hiding some of the content.
The other option is to have it "push" the content to the right. The downside to this is that if you have a small screen (laptops for example) it will push some of the content off to the right side of the browser window.
The question is which does the community prefer?