At this point I realised that adding moss only from alphas might be quite a stretch so I applied a quick layer pass of moss, quite randomly scattered so it would tile well. Now when I work in the alphas of cracks and other growth I can have something underneath as a foundation.
I could vertex paint more in CryEngine but for now I will leave it at that, I am still unsure how effective that process can be, I am also debating whether I should make gloss maps or not, it might be quite interesting to set the level in a damp, rainy atmosphere, however that would reflect back on a more dull lighting setup.
Here are the final renders from marmoset.
Here are some screen grabs from engine, my tram rails do darken the ground quite abit, which I wasn't expecting so it may be interesting to put some vibrant assets under there. More to come!