Here's a video done last night with an ASI 120MM.
I will need to mount the scope to do further tweaking as it is cumbersome to collimate and shift the OTA back on the table to recenter the star.
PS: I measured accurately tonight. The distance from the scope aperture to the star was 46m and the diameter of the smallest inner dark disc where the star sits in the video is 4.7mm across.
and a
focus sequence with Bahtinov mask [7.5MB].