if all shapes are not packed, this means the tools has stopped after a number of calculations.
There is 1 millions of trys, so just put 10000000 (10 millions) and it must work
I think it could be good you mark your pieces, if you have a place hidden you could make sort of barcode.
If engraving is possible OpenNest has some single font. I also have Cistercian number in Nautilus