For a 26" wheel, figure on 1x only, even for 36 spokes. I've only built one of these into a wheel, and that was a 26". Thought I was going to do it 2x but it didn't work. Had to go 1x,, and it turned out fine.
Now that I've said that, check that the new models have the same flange size as the older ones. I know they have changed the hub somewhat.