I did this recipe a couple of weeks ago and yes, it's fantastic. The timing is a bit of a pain, as he's very specific, but still worth it.
However, after looking at dozens of recipes for lox, I haven't yet come across any that reference a second brine. Most just use salt and spices in a dry brine, then smoke.
Is it just a flavour issue, or texture? Anyone done a single dry brine only?
I'm not sure, I thought he had answered this more fully on his original post. I do know that part of the reason was for the texture he was looking for.
There are generally two curing methods. Wet or dry. Gravlax is done using a dry cure. Some lox use a wet brine. The dry cure will pull a lot of water from the fish giving you a firmer texture. I usually just to a wet brine. I like the silkier texture