Since https://github.com/theforeman/puppet-foreman/commit/0a6966ce22111b1ce592b5e215a948b3734680e7 (included in foreman-installer 1.12) there are --foreman-max-keep-aliverequests and --foreman-keepalive-timeout parameters. There used to be an overlapping setting for MaxKeepAliveRequests in the katello module but https://github.com/Katello/puppet-katello/commit/5de2e01795aac52e84cd88dc5d57b0841de8657e removed this (included in katello-installer 3.4).