That’s interesting because I get the same error messages (using an unsupported kernel etc). Maybe downgrading will make it work, even for RPi 5.
I found a youtuber who claims to run ReSpeaker 2-Mics Pi HAT on his Raspberry Pi 5. He is using Linux raspberrypi 6.1.0-rpi7-rpi-v8 #1 SMP PREEMPT Debian 1:6.1.63-1+rpt1 (2023-11-24) aarch64 GNU/Linux
We could try old images, made just before 2023-11-24 from the archives:
lite_arm64
Or downgrade even though it’s risky to something like https://github.com/raspberrypi/firmware/commit/26e180f6890f1b4b1c57cdd0a8b61ada3d0ccb1c
But a real solution would be great to find where we can use the latest updates.