I really appreciate you bringing this perspective into the discussion—it pushed me to step back and evaluate the architecture through a deeper security lens.

You make a solid point regarding non-repudiation. For internal single-tenant PLM workflows, native platform audit logs serve as the system-of-record for standard compliance. But when crossing external organizational boundaries where financial disputes or strict legal proof of data delivery are at play, standard database logs aren't enough—we need cryptographically signed receipts (like post-stream byte/timestamp proofs committed to WORM storage).

Looking across the series, I can clearly see where that pattern adds value: extending Part 1's streaming model with signed delivery receipts if external supplier integration requires it.

Thanks for raising a point that opened up such a great architectural deep-dive—always valuable to add another pattern to the toolbox!