The purpose of this video was merely meant to replicate the issue in question. I have also done this before with the space thickness set to the actual values for the specimen and the loading time was unaffected.
I was using the Scissors tool because this is what I had been explicitly told was Slicer 3D’s equivalent to the Lasso tool in other CT software when asked on this forum previously. See attached link. The description I was given of the Draw tool implied it was not suitable for creating a complex segmentation or trimming the results of a thresholding because it was said it would overwrite if a new region was drawn.
I can do this. I had thought I was using Slicer 5.8.0 but I suppose if the filename said otherwise it must be the case. When I had checked the documentation it said 5.8.0, but I wonder if what happened is that I downloaded the newer version but forgot to uninstall the old one, so when I searched for the program documentation it brought the newer file up.