The majority of storage errors I've seen since using BTRFS and ZFS everywhere have shown up only as the storage returning corrupt data and claiming it to be good. I've seen drives and SSDs return dozens of errors per month for months on end without any SAS or SATA errors or any SMART errors.

I've seen this in DC grade SSDs, NAS grade hard drives, and SSDs sold in high end laptops.

This can happen, after all HDD firmware and the link is not flawless. But have you actually ruled out RAM/CPU as the primary cause? I'm skeptical.