JavaScript to Change Menu Navigation Restrictions at Runtime

I know this is a little old, but I was curious and looked into this a little. I exported an HTML publish version with the value set as 'free'. Then I applied git version control to the folder and replaced what I published with a 'restricted' version. This just lets me see which files hold any differences in the whole published package. 

Besides a number of ID numbers throughout, there seems to be some changes related to this in the 'frame.xml' file in the 'story_content' folder where the values changes from 'free' to 'restricted'. There are also some changes in what appears to be a randomly named .js file in the 'js' folder. The data.js file loads the xml at some point so you could see where that is loaded to. 

Hope this helps in some way. At this point it might be easier to build your own custom side nav then try to dig into updating this.