The modloader appears broken for me, it does add the files correctly but after doing some (rough) digging around, it doesn't appear to add to www/js/plugins.js properly. I got it to work by going through the modloader first, closing the game, then manually adding a newline to that file myself, along the lines of mods/patches/MODHERE/js/plugins.js while copying the formatting of the pre-existing ones. This obviously isn't the proper way to do it, but if you're really desperate you can try.
As for the wrist cuffs, I found it in the last challenge from the Chroma Center Restraints testing place (it's underwhelming). Have yet to find the new sidequest interface.