Just checked it with the RC1 build and it seems to be working fine. Just load two or more different objects that you want to scatter (can be from Cosmos), create a Scatter, scatter your objects over some surface, enable clusters under surface scattering, and make sure that you are using a correct "size" value. For example, if your scatter-on geometry is 10x10m large, you probably don't want to use 1000m or 0.1cm as the size. A value of 1m would probably work well, making each cluster about 1m large.