Cardboard Spool Replacement - Printable Threads

Every other ERYONE spool I have found uses ISO threads, which are difficult to print cleanly with PETG as they have a 60° overhang. This generally causes issues with internal threads as the filament may not bond to the lower layer and spider web over to another point in the arc. To combat this, I created this spool. It has 45° trapezoidal threads so it can easily be printed quickly at large layer heights without overhang issues. This is a no frills spool, with holes on only one side. The core is