That's an unfortunate issue you have there...
By the way, here's Tyvan's official reply regarding on this matter as he can't respond here due to some technical issues he encountered:
Hello everyone, this is Tyvan from KZ official. First of all, thank you for your attention to our product, you know there is nothing that makes our day better than getting an email from some random person in the universe who just bought a PR2 in the US and tells us the story of how it's the most amazing planar IEM they have ever brought home in their life, that is what keeps us going. There is nothing better than getting better, that is what drives us. So does PR2.
Everything is the same as the previous one, with the same driver and graphics. But after we improve the PCB, the production efficiency will be higher, and the accuracy and consistency will be better at the same time. The mesh is the damping mesh. We stick a damping mesh on the speaker before, but the previous design with the mesh with potential risks to consistency, which also cause low production efficiency. Now, after we upgrade the PCB, meanwhile, changed the damper position to the outlet nozzle, and the mesh is not required.
-- Tyvan Lam, KZ Representative.
I just relay his message from our private chat in FB. Thanks.