do you have a need to bridge it?
if you don't want to use the wireless of the westell, just shut if off.
i have mine set this way:
have the coax from the ONT going to the westell.
have another coax point in the house and put a MoCA on it...the output of it is an ether cable that i take to my other router (a netgear). i use the wireless of the netgear for the laptops, a hard port from it for the desktop, and the routers ports of the westell to the TV, game console, and bluray.
is that similar to what you want?
the westell isn't bridged and i use the dhcp of it for the whole setup (the netgear actually points to it as its gateway)