After firstboot ignition isn't needed in initrd anymore. It takes up 10MB of
space which is significant on slow ARM devices. How about adding a check()
function to the dracut module that only installs ignition if configured to do
so?

In addition could also trigger on existence of eg
/boot/writable/ignition.firstboot. So the kiwi build would include it but as
soon as the system is booted, further mkinitrd would omit ignition unless
customer configures it to be included again.