FTA:
“Well, Apple defines that, but I guess that’s kind of a pain to figure out and it’s just easier to try to decode and see what happens! YOLO!”From what I understand (also FTA: “The Unity IAP team found themselves having to harden their code against random data”) the fix wasn’t to read the documentation and do the right thing, but to go deeper in on “if we step carefully through this minefield, we probably will survive”.
And Unity’s customer is happy with that!