Fair question, and I see now the six decimal points on the title of this thread, while empirically derived, are less useful than a moving average. Let me explain again.

1. 178.867624 = Average SSB period 1500-2099 (600 years)
2. 178.83 = Average SSB period 1500-1680 (180 years)
3. 178.92 = Average SSB period 1920-2100 (180 years)
4. #3 - #2 = 0.09 years slower over ~500 years.
5. #3 = Great Year/144 (current value)

I calculated points 2 and 3 in response to the query from Nowhere Man about the significance of the digits. My initial hypothesis was that the rate of change over 600 years would be too slow to detect, hence that a 600 year average would be useful. However, as shown in the subsequent chart I posted, the clear steady trend of ~0.1 year slower over 600 years means that #3 is more accurate as a current figure, so this has refined the claim.
The biggest departure from trend in this chart is a sudden slowing around 1750, otherwise all data points are right on the trend line.
Long term I suspect this data is a small part of a long cyclic pattern. It can’t have been slowing at this rate for ever. For example, the SSB cycle might slow down while the solar system expands and speed up while it contracts, in self-correcting gravitational phases of planetary orbit radius. Does anyone know?
I am simply trying to understand this near-constant SSB pattern in scientific terms. I have called it the pulse of the sun, and consider it is central to the structure of time because of its exact harmonic alignment to the Great Year of lunisolar precession. There is obviously immense potential for unfalsifiable speculation about this new discovery, but here I would like to discuss its scientific side. For example, is the rate of change of precession known?