Persistent static routes

Assuming a RHEV 3.5 hosted-engine installation with RHEL 6.7 hosts, what is the 'supported' means of adding persistent static routes to the hosts?

While I can add static routes temporarily using 'ip route', these obviously will not survive a reboot.

I assume that I can manually add the routes to /etc/sysconfig/network-scripts/route-rhevm, but as this file is maintained by vdsm I'm worried that any static routes I add to it may be lost during an upgrade or vdsm configuration change.

Any insight/guidance would be greatly appreciated.