Focus shifting with different focal length.

As far as I know there is no way around it, I have the same lens and just ended up calibrating it for the focal length I used most often, 200mm. Mine was ok at shorter lengths, though whether that was down to sample variation or I dont have as critical eye as you I dont know!
I imagine the sony 70-200 would be built with tighter tolerances but I've never owned one, maybe someone else can help there, though if it suits your photography maybe a minolta 200mm 2.8 is the only other alternative?
It will be interesting read what others recommend as its something thats bothered me also.

Edited by bigsi - 02 January 2021 at 10:05

There's a couple options, you could split the difference and micro adjust at 135mm and see if you get acceptable results throughout the range. If time is not a factor in getting the shot you could dial in at one end, record/memorize the setting for the other end and adjust when needed with just a couple button presses.

The main issue is that Sony does not assure that MFA will work with non-Sony/Minolta lenses.

I had the latest Tamron 70-200 that did not adjust at all with MFA. I also had the 28-300 PZD that had a knee at about 70mm that caused a problem since the wide and tele end points of MFA assume a monotonically increasing/decreasing slope to calculate intermediate focal length corrections. The slope was shallow from 70 to 300 and had a diff of about 2 between them. The drop from 70 to 28 was about -5. I sold both lenses.

I now have more Tamrons, the latest SP series that are supported by the Tap-in Console. I have determined that each lens works as expected for MFA with my a99ii without the need for the Console. Go figure.
The are the Tamron 45mm, 90 mm macro and 150-600 G2 (2 copies). I am particularly impressed with one of the 600s where the MFA for 150 is -2 and 600mm is -7. The values selected by the camera for intermediate focal lengths are the same values I would have used based on the work I did characterizing the lens, thus I set the Tap-in Console values to 0.

My Sigma 50-500 late-model zoom (also OS) was a sweet lens that required the MFA to be different by only a unit or two, I do not remember any issues with it.

It seems Tamron has caught up with their latest lenses to the Sony MFA software.

I would fully characterize the MFA for each labeled focal length of the lens to determine if you can indeed choose a meaningful value. If using that value does not yield good results with your a77ii (a 1 MFA value per lens design) then maybe you will choose to purchase a Sony/Minolta lens.