And then you will find that your focus is no better than if you just turned off AFMA. The setting is not something that you can average based on a set of bad values. You can be off by 1 but any more than that and you are off. 1 AFMA is 1/8 of the depth of field. For most telephoto lenses where AFMA makes the biggest change being off by 1 wide open makes a difference wether the eye of you subject is in focus or not. There can be no guessing and no averaging of test values. The setting has to be exactly where it needs to be. The dot method doesn't get you there. You still need to run your photo tests and dial in the setting.
To those have made repeat measurements and have found different values - you are experiencing the life of a scientist. All measurements are subject to random and systematic errors. Just repeat the experiment several times and use the average value, unless some of the values are absurd. Errors can obviously arise from the initial focussing or during the dot confirm. I would not consider a series of AFMAs of say for example 2, 6, 4, 3, 3, 0 to be wrong but merely a mean of 3 with a not unsurprising standard deviation.