Autofocus vs previous focus

Im curious on your thoughts on this.

For the very first step of the focus routine, it does not shift focus but first compares it to the last confrimed focus, if its within a definable tolerance, skip the rest of the procedure and carry on as is?

I have thought about this as well… the problem is usually with altitude and seeing. Since HFR is inversely proportional (maybe not proportional, but…) to altitude (HFR goes down as you move toward zenith), getting the same or similar HFR value, it is hard to tell if you are still in focus or if, due to better seeing, the HFR has stayed close to the same, but you are now out of CFZ.