As was explained already, we just can't replicate this. I don't see any ground bleeding, either with the default mesh, or with the FS Genesis, provided the two mesh complexity sliders are set to 100, as explained in the patch readme.
However, the 100 level is needed only with the FS Genesis mesh, to allow our own higher-res mesh to be displayed and fix the FS Genesis one. With the default mesh, the mesh sliders can be set to lower values as well and, in both cases, there is no ground flickering or bleeding.
Note that, this can also an video drivers issue, like a problem with the Z-buffer settings, that might be either bugged in the drivers, or might have been wrongly set by some tweak utilities.
Also, remember the scenery is only compatible with DirectX 9.