From watching the entire show, as well as playing SWN for over a year, some of the house rules I've gleaned are.
Giving skill checks the same 6- 7-9 and 10+ divisions as most PbtA games, and including partial successes. By default, SWN has a binary pass/fail with a fictionally/arbitrarily chosen target number.
Giving players the ability to help each other on rolls. That's not a thing in the rules.
Using Culture skills similar to Circles from Burning Wheel is new as well. Culture is normally just knowledge/behavior.
Also, at character creation he had the characters start at max HP instead of rolling for it. For future levels he used the mechanics as normal, but he didn't want characters with 1 hit point.