Answer by jhcaiced for Is there any shortcut or add-on for Firefox that would allow going back to previous view position (within the current page)?

An interesting question, maybe this addon can work for you:

Book Text Mark 1.1.1by Roman Mironenko

Use context menu or Bookmarks menu to set mark lines within long pages. Navigate to marked pages and to the marked lines.

Highlight interesting sections of text, navigate between highlighted sections.https://addons.mozilla.org/en-US/firefox/addon/book-text-mark/