I've watched these 4 videos. Interesting indeed, but John Carruthers forgot to mention that the very first point is to perfectly tune your bass with a strobe tuner like the TC Electronic or the Peterson. Then the steps 2 and 4 must be reversed. Why ? Because if you do the action and the nut height before the intonation, when moving your saddles to the right position and filing down or raising the nut will modify the action itself...
My little trick is to begin to set the action by the higher pitched string to your taste and put all strings of your instruments at the same height, then raise each next lower string a quarter turn higher than the previous one, so if you have a 6 strings bass, the G will be 1/4 turn higher than the C string, the D being 1/2 turn higher than the C, the A being 3/4 turn higher than the C, the E being 1 full turn higher than the C and the B being 1 and 1/4 turn higher than the C. This way, you'll have a perfect stings radius following your neck radius with just the right amount of height for each string.