I'm just guessing here, but I saw in the description that the grass and weeds aren't modeled, they are Alpha planes. So for them to render correctly in Superfly, I guess you need a lot of Transmission Bounces, since every plane Needs one bounce. I would start with 20 and see if it makes a difference.

A ship in port is safe; but that is not what ships are built for.
Sail out to sea and do new things.
-"Amazing Grace" Hopper

Avatar image of me done by Chidori.