XB7/Fiber setup and Home equipment

Hi!  I have my own equipment (a Netgear RAX 200 router) and I would like to use that for routing traffic. 

I have an XB7 Gateway and Fiber setup.  Right now, I cannot place the XB7 in bridge mode because the inbound connection from the ONU is sent over ethernet into the primary port of the XB7.  When bridge mode is enabled, no other ports of the XB7 can be used, thus there's currently no way for me to use my equipment.  I have never used MoCA before, just read a little about it.  Is it possible to send my ethernet connection from the ONU to the XB7 over MoCA - thus utilizing the XB7's coax port and freeing up the primary ethernet port on the XB7 to use with my own equipment? 

If not, is there a better/more sane way to do this?  This does feel a little insane.  

Thank you!