The Vedic, as far as I know, is restricted to verbal account. My precession model (DIY instructions in EarthGyration article) pinpoint commencement/midway/completion: 1250 BC min.obliquity - being one turnaround point, the other 14210*BC max.obliquity - two diametrically opposed eras -- 13 millennia apart -- each associated with Equinox, which we recall incur two geographic locations on opposite sides of Earth's equator.
The information was translated from Sanskrit. It's origin has not been disclosed, but someone, somewhere, sometime, somehow became aware of precession and recorded it.
As you are aware the Vedic model and your Earth Gyration model differ. However, there are similarities in results.
As agreed, the Start Point of the Great Year is paramount. After that, barring any catastrophe, cosmic mechanics should run smoothly. And even with an upset, a reset can be done.
The Vedic Great Year has a Start Point at the Autumn Equinox at the first point of Aries by the observation of a particular fixed star. Whether it was a heliacal rising or not, is unclear.
This particular event is said to have occured in the year 11501 BC when the Sun was in a certain position with relation to our galaxy, the significance of which, has not been discussed.
Your model suggests a Start Point at 14210 BC with the maximum obliquity of the axis, if I understand you correctly, and is also associated with an equinox.
Allowing for the 2000 year difference in the proposed Great Cycle, the Vedic Start Point, could possibly be approx. 13501 BC which is 2.7% of the Cycle. Or, the other way around. Not perfect, but acceptable for further research.