SASANO Takayoshi <uaa@mx5.nisiq.net> writes:

> And, alsa-lib/alsa-utils(aplay)/alsa-plugin(Pulse) combination is working
> on OpenBSD-7.4/amd64.

Did you also test without pulseaudio e.g., via sndio plugin?

https://github.com/Duncaen/alsa-sndio
https://repology.org/project/alsa-sndio/versions