Dmitry, what exactly are you missing? Foreman is capable of booting BIOS or EFI SUSE systems. You will likely need to add Grub1/Grub2 PXE templates, you can do that by modifying the BIOS ones. Our SLES/SUSE templates are mostly done by the community.

https://github.com/theforeman/community-templates

Example for Red Hat systems:

https://github.com/theforeman/community-templates/blob/develop/provisioning_templates/PXEGrub2/preseed_default_pxegrub2.erb

The one for SUSE will be very similar. Here is PXELinux one you need to convert into Grub2 format (above):

https://github.com/theforeman/community-templates/blob/develop/provisioning_templates/PXELinux/autoyast_default_pxelinux.erb

And then test it.

Applied in changeset foreman|57ac86bf7aebdad8d3b6c7cca297f2e75a9ced63.