when you press (Start)
this tool clones all sub tools
and by cloning it keeps the subdivision levels
this allso put the sub tool on top of the pallet >User 3D Mesh

all sub tools are save to the ZPlugs folder and keeps the sub tool name.

when you press (Merge all)
this make all sub tools 1 Mesh
when you Merge all, it save each sub tool as a polymesh 3D
each of these sub tools have no subdivision levels

all sub tools are save to the ZPlugs/MESH folder.

this has a (slider)
this sets all sub tools subdivision levels at equal value.

video
http://www.ezbrush.mediabakers.com/Ver3.1-EZ-mesh1help.html