Use the Navigator (View > Navigator > Show Navigator). When the Navigator pane appears, make sure it shows "Table of Contents". If you haven't already assigned chapters and sub-chapters a Level, then do it now (Tools > Table of Contents > Include in TOC > Level 1). For a novel you won't need more than 2 or 3 levels, I think. Create shortcuts for the levels you want to use. 

Now go to a place in the document that you want to work on. Select the beginning of the passage and assign it the Level 9 (or some other Level that is not being used). You will immediately see the beginning of the text showing up and be indented in Navigator, so that you will be instantly able to spot it. Repeat for all passages you are working on. 

You should now be able to jump back and forth VERY comfortably, even in a very long document.

The following screenshot shows a part of the novel "Lord Jim" by Joseph Conrad, which is a long novel indeed. The chapters have been assigned the Level 1, and the indented lines are Level 6 and 9 respectively. Level 6 and 9 have a different degree of indentation. Suppose you choose Level 6 for passages that you want to completely rewrite, and Level 9 for passages that contain facts that need to be checked before the novel is sent to the publisher. In the Navigator you see at a glance where each passage is, and jumping back and fort literally only requires one mouse click.

After you have finished working on a certain passage, you simply select the text by clicking once on the line in the Navigator, and then hit the Delete key. The Level assignment will be deleted, and the text line will disappear from the Navigator. The text itself will NOT be removed from the document.

Best,

Þorvarður