Worked fine for me.
Just one recommendation, the breaklen seems a bit small if the material thickness is thinner than your examples.
e.g. I have a material thickness of 3mm and also 2mm and this results in a breaklen of 1.5 and 1mm respectively.
So my box broken on one of the hinges as 1.5mm is too small.
I guess it depends on the material thickness but I changed it to
/breaklen materialthickness 1 div def % How long should breaks in the hinge lines be
/breaklen materialthickness 2 div def % How long should breaks in the hinge lines be
Or perhaps some people may need to manually set this to avoid breakage.