I had a look into the image https://packages.pyra-handheld.com/images/buster/-> test33.img.7z. It contains the kernel 5.6.19-daveiii-pyradef-aufs. Doing grep -i uvc /boot/config-5.6.19-daveiii-pyradef-aufs returns # CONFIG_USB_CONFIGFS_F_UVC is not set
Looks like you either need to compile a new kernel on your own using the current configs in the /boot folder as a base. Or you communicate somehow somewhere that this config should be enabled in the pyra kernel. Second option would be better but I don't know where this would be.
To complete the post: For compiling a new kernel, the corresponding source would be needed. I think this is available in https://packages.pyra-handheld.com/unstable/ -> e.g. linux-5.9.13-daveiii-pyradef_5.9.13-daveiii-pyradef.orig.tar.gz.
I was just going to ask @aTc about it. Also I/O accounting support would be nice, so we can see what processes are writing what where. The Pyra has a pretty big internal storage, so it's probably not necessary to slim the kernel that much, right? Or is there some other reason?