Yup, you're right. Thanks for pointing that out @mikeslr
All those I tried have vmlinuz and sfs files that I had to rename to zdrv_bionicpup64_8.0.sfs. So if the driver/modules are specific for that kernel version, I'm back to my old question, why didn't the audio get any better? Not configured properly before getting compiled? Missing components? Maybe there's is hope then.