Nothing to worry about_ you're good. Those "nodules' form when the branches are stressed from pulling on them_ kinda like stress fractures. But don't worry, like bones when they heal they are now stronger than before.
I get them all the time from aggressive LST. They seem to form most often when the ties are placed on the branches too close to the plants trunk_this seem to put more pressure on them than if you first set the ties further out on the branches. You can get similar growths when you super crop a branch, but where the branch was squeezed and bent over not where the branch grows out from the trunk. Happy growing!