Hello again MoCommodore,
I am afraid that for such a feature to work - the information will need to be recorded inside the PDF file, and the PDF Specification does not give provisions for it, so it is unlikely that this can be implemented, as writing information inside a file that is not conforming to the PDF specification is not good practice.
Some features we can implement even if no provision is made in the specification directly - but for those we do store the information in the software, and it will e.g. only work in our products, but will not break compliance. So that is why we do remember where you were in the file, but have to do it outside of the file itself.
It should be pretty straight forward and quick to create bookmarks with the Editor. Just select some text from the current line you are on, and Press Ctrl-Shift-B (or right click -> Create Boomark), and you will now have one to the current page. You can then remove the previous "READ" bookmark and continue from the new one the next time you get back to reading this file.