I have a 30 watt rayco fiber laser. I am using lightburn 1.7 currently. I have a rotary that when I enable the rotary and draw a line in the center of the work grid and hit frame to center and align the rotary, the line is as far right as it can be on the laser table. to get it centered i have to arrow the line all the way to the left of the work grid to get it close to the center of the cup on the rotary.
Check this out, Output center should be 1/2 of your work area +/- depending on how close your rotary is centered. I found it in split marking but it applies to all rotary.