initial configuration was 2 nylocks on the top two caps and two on the bottom caps then two regular as you have to encapsulate the top and bottom pcs with 2 nuts each position for a total of 8 nuts total.
However the configuration can be switched up to having all regular nuts or 4 nylocks and 4 regular or could be 6 regular and 2 nylocks.
I had originally posted what I had used initially.
Since then building several machines I have found that the 6 and 2 you mentioned is the easiest to use to put together. But putting all those variations on there would just serve to confuse people so I left it as is on thingiverse.
Hope that helps.