Three days on and the Highness is now running at about +5 seconds per day 🙂   Trying another tiny shift of the fine adjuster:

Now it’s down to just a few seconds per day, moving the adjuster screw by a very small amount is quite difficult! Let’s see how close I can get it, +/- 2 or 3 seconds per day would be very nice but I guess that is unlikely through use of a screwdriver, albeit a small one, and a steady hand 🙂