Is it better to do all the calibration in one step, or to do each in turn?

MaxIm DL is designed to do all the calibrations in one step; there are a number of subtleties to calibration and the software knows how to handle them, but only if it knows all the calibration steps you are planning to do. It is strongly recommended to do all calibrations in one step, and do NOT perform any modifications on the raw calibration frames beforehand.