Nice work Guliver,
Yes, there should be a preconfigured upgrade patch to help people take advantage of newer code written to enhance OS3.9.
If I had more free time and just a little more confidence in my ability to script such an upgrade program.
Thanks for doing the research and providing the list of your steps. I hope other knowledgeable Amiga users here will review it and make their own recommendations or alteration to your steps, so a consensus can be attained regarding the best upgrades that should be used. :-)