Really fantastic scape. How exactly were you planning on growing mosses? Attached to additional rocks, or are you planning on adding driftwood?
You're the first person I've seen using Malaya. Very interesting.
There are a couple folks in So Cal with Malaya. In my case, I knew I wouldn't be looking for intensive plant growth but wanted a good substrate. The brown color also looks good with the rock and sand. There will be a lot of substrate visible so i didn't want to try and blend/hide the black Aqua Soil.
As for the moss, I will attach it to small rocks and fit it into a few crevices.