Using foreman-xen

I have been experiencing with Foreman for a few days now and got to testing
provisioning of new CentOS VMs on a XenServer cluster using foreman-xen. I
am having some issues:

Use of PXE boot is not viable option, when deploying VMs from XenServer I
simply select "Install from URL" and specify the URL for our CentOS boot
media. For Kickstart file I simply append to the "Advanced OS boot
parameters" the URL for the kickstart file, the kickstart device, IP
address, network mask and gateway.

I could not find a way to do the same with Foreman and foreman-xen.

I appreciate, any help to point me to some documentation or what would need
to be changed on the source for foreman-xen to accomplish booting from the
URL that has a CentOS boot media and specify kickstart parameters.