default kickstart configuration (beyond interactive-defaults.ks)

I'd like to fix: https://pagure.io/atomic-wg/issue/226

Right now for Atomic Host, we embed the ostree content inside the squashfs,
with the goal that users of the ISO don't have to hit the network.  We hook bits into
interactive-defaults.ks; see this change for how it works:

https://pagure.io/fedora-lorax-templates/c/e34c371501d6eac75925aae86bd737c8a43d8244?branch=master

However, if one wants to then extract the ISO to do a kickstart install, the
user must repeat the `ostreesetup` bits:

https://lists.fedoraproject.org/archives/list/[email protected]/message/M6CEAGA3RGXZLSZ5GWSCTMMOV5OOXUUN/

Specifically from his attachment:
ostreesetup --osname="fedora-atomic" --remote="fedora-atomic" --url="file:////run/install/repo/content/repo" --ref="fedora-atomic/25/x86_64/docker-host" --nogpg

which is really internal implementation details that I'd like the ability to change
without breaking people's kickstarts, and conversely not require them to specify
by default.

Are there any facilities today for a "default kickstart" like
/usr/share/anaconda/interactive-defaults.ks, except not just interactive?