Starting from v2.0.2, I am just impressed how good structural meshing now works with the new Mesh Refinement for compounds. I would like to share some positive observations, using a bolt-model as example:
The CAD model is created with the shaper-modul inside salome. All volume partititions are already done here, so that the compound consists of 116 six-sided parts. For some reason this specific model must be imported as brep file to get a compound with solid-parts in prepomax, importing it as step file i only get shell surfaces.
The next observation is, for a structural hexa mesh the value for the Min element size can be higher than the later used value for a refinement. So this is only necessary for creating refinements for tetra meshes.
Using mehing_parameters with a huge value for Min and Max + Transfine_mesh (Recombine = Yes) creates a hexa mesh with one element per volume.
Next i use mesh_refinement for the shown 4 edges (alternativ the 4 faces could be selected). The detection of finding all opposite edges, where this refinement has to be projected to, works very good so that it is not necessary to select all opposite edges as well. 
Plus, the whole thing works the other way around too: Starting with a fine mesh and then using mesh_refinement to coarse selected regions:
In the next step you can then create two element-sets for the upper and lower sections and convert them to parts to have the needed cutting-plane where pre-tension can be applied to (the remaining part is then empty and can be deleted), unfortunately this leads to losing the associativity to the geometry based mesh creation. On the other hand, when having a model with many bolts, it makes more sense for me to mesh one bolt and use the transform option to copy it several times to minimize the meshing effort, in this case the associativity also gets lost.
By creating the element-sets, in some cases the “Geometry based selection” works not always proper, means that sometimes some inner elements will not be recognized. Here i suggest to use the “FE mesh based selection > Element” instead:
The only option I would like to have is, to be able to specify the number of elements or nodes per edge as an alternative to the element size. Anyway, I’m thrilled. 