I was having trouble of my hinges being too fragile when bashing in a 3mm rod, leading to them snapping the hinge irreparably.

So here's a pin to fit the hinge.  It's obviously not as tough as metal, but seems to do ok.  Note that the opening of the lid will become limited to about 100 degrees with this.

Prints without supports (if laid on the longest surface).

Total mess of a FreeCAD file also attached (v0.21.30143) :).