The roof supports should be curved, and the whole area is too narrow. You could use vertex painting (there are a bunch of examples on youtube) to blend between grating and fungus. The roots would probably be best as geo, and a couple of floating planes around the thickest parts for more volumetric fungus.
(wall of text incoming) Hi guys i thought it would be a good idea to post this up here and get a few extra crits and tips as i'm chugging along. i'm gonna try and be as in depth with this as i can in the hopes that it will help myself and y'all, but i'm by no means an industry pro so please be harsh as i would really would…