Don't fret! ✌️ It all makes more sense if you remember that every set of 4 permutations requires 20 trigger steps and that those 4 permutations come about using 5 X 4 steps to trigger the quad sequential switch where, crucially, every 5th step is muted, hence resulting in cycling through the four different input sources coming into the sequential switch. The main task of the octal switch is to change the inputs to the sequential switch every 20th step. Hence creating a new set of 4 permutations every 20th step using the method I described initially.
Seems to me, there ought to be an Ornament and Crime app or Monome Teletype program that could generate the 4 permuted triggers required for this, and completely eliminate any need for switches.