I found this, which would make me believe that there are no modules (currently) that might possibly support /dev/snd/seq included in the kernel used in image69.
$ grep -i sequencer /boot/config-5.15.0-starfive
# CONFIG_SND_SEQUENCER is not set
$
I guess you could grab the kernel source for the VF2, copy and modify the booted config (/proc/config.gz) and attempt to build your own custom kernel using the instructions to build a linux kernel that are part of the SDK quick start guide.
One thing to keep in mind though is that it may not even work, it might require additional changes, maybe play it safe add a request for support in the improvements for the next image release.