I've just used the new `pkg.linux.unsigned` profile to build myself a 7.3.1 and
it worked almost fine: the only problem was that after installing the built
packages, the image was not copied from `/usr/lib/modules/${kernelRelease}/` to
`/boot/` and as a consequence `update-grub` did not add it to my Grub menu.
I'm guessing that the reason is that post-install scripts expect image files in
`/usr/lib/modules/${kernelRelease}/` to be named `vmlinuz`, while when using
this profile, it is named `vmlinuz.unsigned`.
My simple workaround is to manually copy the image to
`/boot/vmlinuz-${kernelRelease}` and rerun `update-grub`.
I use `linux-base` version 4.17~bpo13+1.
Best regards!