Focus Offset setting?

I have found out that I can get a better focus if after a auto focus run if I move the focuser out 3 steps. For me that’s 3 x 5.5microns.

The focusing is working fine and I get great ‘V’ curves, but I noticed that there was a difference of three steps when comparing focusing using the Bahtinov mask with the Bahtinov mask grabber and a focus run done straight after (with very stable temperatures so I know that is not an issue). I should add that, these were both done with the same clear filter, so there is no issue about the filter offsets being out (which was my first thought).

So my question is can you add a feature to add or subtract a number of steps to be added after each focus run. FocusMax already has this feature called ‘Focus Offset’.

I can fudge it at the moment by adding an extra 3 steps to all my narrow band filters in the filter offsets, but what if I want to image with my luminance filter. I have the autofocus set to focus using the luminance/clear filter.