Interesting, I wondered about that. I deal with magnesium deficiency a lot with my keto diet to control diabetes, and it is quite possible that this is the issue. I need to supplement magnesium in order to avoid nasty (really nasty) muscle cramping, but did not know that restless legs was part of the same problem.
For some reason, the keto diet causes loss (or inadequate absorption - dunno) of both sodium and magnesium, and possibly other cations. Keeping the electrolytes sorted has been the biggest hassle of the diet for me. I have to keep my salt intake up too, and even with substantial salt intake, my blood sodium levels are still low.
Thanks for the head's up.