The only different between what we do and the videos is that our jobs have to be flush with the right side and we use a jig for the hold-down
I've done quite a few double-sided projects how and a couple things I do that make things easier are:
1. I set the material in a jig instead of using pegs.
2. So the material sits in the jig perfectly, I will 'square-up' all sides, sometimes making it slightly different size then what was used in the job setup. (Which seems always the case if I have glued-up the material) For that reason, I will center the datum rather than using the corner as shown in the video.
3. Make sure the model position is centered in the material (under material setup). My personal preference is using the Material Surface for the Z-Zero in case the material is slightly thinner different from the job setup.