FSD entitlement tracking

It could be interesting to track state (sort of like AP version) on the FSD feature entitlement. 

I'm wondering if, along with model time, geography, and AP, having purchased FSD might be figuring into the available firmware version pushed to cars. Through tracking entitlement, it might be possible to determine a pattern to the firmware pushes. 

As a for instance, I have a 2021 ModelY, with FSD, and the "advanced" firmware option selected, and still only 2021.4.21.3 is made available by tesla. There are no fewer than 10 firmware versions which are newer than what is offered, and have a combined % of fleet of around 80%, with the number of Ys running 2021.4.21.3 not changing for days. I wonder what could be leading to this. 

I wonder what else could effect this, and how we could track it better understand that black box that is firmware deployment.