Yes, first is clustering. Curently you could simulate clustering by using multiple CScatter objects on one surface plus density maps. To manage this inside one single Cscatter object we would need to be able to map the frequency parameter. Not possible atm. so it´s hard to setup but works when doing a fixed clustering "manually" with maps.
Second is material variation. Corona Multimap in instance mode does only half of the job because you can only affect what is called "Item" in ForestColor map. The "primitive" mode is useless here. If we would have the highly requested element/polygon mode we could even simulate the "Item <-> Element" slider of the ForestColor map with cascading and mixed Corona MultiMaps :)
Third would be a global tint map which can be achieved by using a
world coordinate map.
So if even complicated I would say if we had element/polygon mode for Corona Multimap it could be done quite similar :)
Good Luck