A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Fleming
Date: 2020 Oct 25, 12:47 -0700
If I'm not misunderstanding your spreadsheet, J7::J11 is time and K7::K11 is lunar distance.
It says that the rate of change of LD with time is approximately 1 moa/1 minute of time.
We know sextant measurements show random variations of 1 moa, therefore hoping for time measurements better than 1 minute in time is not going to happen withou some new innovation.
This is consistent with the 2 minute difference between your times observed. Their cancelation in your averaging is pure chance.
Any cancellation of systematic effects would happen with the individual measurements even further from the known time.