120, 140, and 160 are all technically fish-eye lenses. The fish-eye correction is part of the lens calibration process, so if you recalibrate you’d redo both the lens calibration and the alignment calibration. (The first is used by the second)
The fish-eye specific calibration mostly affects the outer edges of the lens correction, and allows the entire output to be used.
For example, if this is your input image:
This is the corrected image:
LightBurn would previously only use the parts of the image that were completely valid, within the red rectangle. The new code allows the use of the entire image, so you may get a small black indent in the middle edges of the image, but you’ll get more usable area in the corners.