@MarkCameronHarris You have to ctrl/cmd-click on the pencil icon in top-right of screen.
However, my problem @Meins and others, is that I cannot link different pages/files in either editing or preview mode. When I link the two desired panes, as soon as I start scrolling, the pane in which I do not scroll changes to be the preview of the scrolled pane.
Can anyone else replicate this?
My desired use case: Translation. English preview mode in one pane. Linked edit mode in other language in other pane. But I don’t know enough about coding/CS to understand if/how panes could be scroll-sync-linked when content could vary completely. Can headings be linked to maintain placeholding?