How can configure FreeSBC to Relay SIP OPTIONS?

FreeSBC is currently set up as SIP FW layer, with a CLASS 4 freeswitch behind it that does LCR but also manage its own gateways (NAPS). Can anyone give me a direction on how to forward SIP OPTIONS still with B2BUA functionality to the class 4's gateways if the class 4 is sending it FreeSBC. I have a similar setup with OpenSips:
1. Class 4 -> Opensips (OPTIONS)
2. Opensips -> Gateway/Nap (OPTIONS-Added Via Header) <- In this case with FreeSBC, Im interested in a new OPTIONS request hiding the CLass 4 details
3. Gateway -> Opensips (200 OK)
4. Opensips -> Class 4 (200 OK)

Please check if Map any response to available status is checked under NAP Advanced parameters. The Map any Response to Available Status parameter is set to consider proxies as available on any response class (including 5xx/6xx). This is required when a peer proxy does not support being polled with the OPTIONS method.

You need to uncheck this feature to work only with OPTIONS messages.