Surely, you acknowledge that the effect is observable and measurable?
But 2000 years is too small a sample to extrapolate with any accuracy.
f you are merely stating humans have never observed and recorded a full cycle, then I agree.
So, with no evidence to prove otherwise (but happy to analyse any results to the contrary), Precession of the Equinoxes could have begun 10000 years ago. Working on this postulation, any decoding of any structures, statues, stones, idols, engravings or whatever, by using a 2160 year Zodiacal Age to accurately measure time is impossible.
Hence, how can one state categorically that the dating method for cave paintings allegedly 40 000 old is accurate, and then use this date to confirm questionable carvings at GT?
Until Year 1 is accurately determined, why are people so eager to jump enthusiastically on the Precession bandwagon?
I seem to recall you have some affinity with the notion of our Sun being in binary motion with Sirius?
Being 50 trillion miles away from Earth could prevent this. But Sirius is in a Binary Star system.
The deviations in precession rate are extremely slight so that would justify expecting minimal effect on an extrapolated precession?
Currently, yes for short periods.
Over 1000000 years the Rate of Precession increases by 500%.
Unless there are massive UNKNOWNS yet to be experienced? Do you know of any reason to expect such unknowns?
Why else try to measure Precession?
It's not required for measuring solar time.