Mediapath in an Installation network without DNS

In one environment we want to use a dedicated installation network, but we faced the problem that there is no DNS in this network. I can change the foreman_url to IP in the settings, but it does not affect the mediapath rendered into the Kickstart. Is there another way to influence it?

Expected outcome:
Provisioning without DNS is possible. Perhaps Mediapath can be set to IP (directly or by using foreman_url)?

Foreman and Proxy versions:
Foreman 1.20 + Katello
Foreman-Proxy 1.20