bcm_nat on Asus AC68

Have gotten gig fiber and am trying to increase WAN speeds. Am currently getting around 325 down, 250 up via Google's speed test. The GUI's "Overview" screen shows a gig connection on the WAN interface.

Using Jacky's tomato-RT-AC68U-AT-ARM-3.4-138-AIO-64K, which I believe is built upon Shibby's version of the same name.

(This AC68U has the Rev B1 hardware. I understand Shibby hasn't gotten the newer Rev C hardware working.)

Following another post tried:
modprobe bcm_nat

and...

bcm_nat on Asus AC68