I have not used iD much as I usually use Potlatch2 which I’m very happy with. I was interested in seeing how iD handled turn restrictions, the answer is very well. It works like this. Start iD, click on junction node. click on the “in Way” and the allowed out ways have a green indicator and the not allowed show red. You only have to click on one of the Reds or Greens to toggle or swap them, Excellent.