I hate that I've never heard of or even thought of this because it makes literally so much sense.
I would've thought from pure logic that it'd be around 10 minutes letting it stand. Tbf I would've thought it's possible to even leave the lid on as long as it has a steam hole as that way you finish letting it steam at the bottom. Stops that sorta soggy wet layer on the bottom of the pan from accumulating, I always do it even if I'm just doing a basic boiled rice. 10 minutes covered on mediumish heat after bringing the water to a boil (you gotta sorta baby it and wait until the water starts rapidly rising up to the top at which point you knock the heat down until it stays sitting and doesn't overflow), 5 minutes on low heat, 5 minutes with no heat and just steaming. With a good wash of the rice and proper rice-water ratio (which your recipe also uses, so kudos to that cookbook) the rice always comes out perfect. I'll absolutely try this though, seems like an upgraded version of this method