Given all the press about the substantial differences in brands of kosher salt, why why hasn't this recipe been updated? Ted?

Great advice, 702551! Would you use that 0.4% ratio here?

For what it's worth - and for those out there who for whatever reason don't wish to use a ratio instead of volume measures - 1 tsp. table salt = 1.5 tsp. Morton Kosher salt = 2 tsp. Diamond Crystal salt, or so says Cook's Illustrated (who I trust on such matters).

Once I hear back from you on this, I'm going to put a comment in the recipe itself. I take it from the comments on the New York Times, where this recipe also was published, that more than one person apparently has used table salt or Morton's, inedible results.

I'm guessing that if Food52 reached out to Sam Sifton to get his permission to clarify which type of salt works here, that permission would be granted. ;o)

And you know, there might be a project here for a journeyman food writer...to revise/update recipes on this site reflecting questions, omissions found and not quite fixed, etc. Writing, when needed, to published authors for permission to add or correct a recipe.
I know, I know, many if not most recipes are submitted by members and NOT edited.
However, readers seem to want a fairly high standard of writing and reliability from the site.
And it's not always there, not even in "test kitchen approved" recipes. For example, i've seen many where ingredients are omitted in list, but included in directions, or vice versa.

Hear, hear!! It kind of amazes me that problems with recipes, when pointed out in comments or Hotline questions, are often never addressed. Some are, but many, sadly, are not.
Thanks for bringing this up. ;o)

While I have not made this particular recipe, I have cooked with this particular pork cut many times and 0.4% salt by weight would be a credible starting point in my kitchen.

Rules of thumbs like this are the best! Thanks again. ;o)