Just wanted to leave this information here in case anyone in the future needs it: I was trying to get the Detailed Equipment and ItemCore mods to work with Mattie's mod loader.
I installed Mattie's mod loader and then only added the .js files of ItemCore and Detailed Equipment into the mods folder inside the www folder. I kept getting an error about "TY" already being defined however, and I fixed this by editing the DetailedEquip.js and replacing all occurrences of "TY" with "TY1". This fixed the issue and now I have no errors and these two mods appear in my mods list in game. Hope that helps somoene!