export particle as mesh has many open edges / overlapping faces / self intersections

[pfg]

hello, 

i want to export the particles as meshes for next workflow. 
the result of the tyflow particles is exactly what i want. 
but if i export the particles to mesh with export operator, the exported meshes are not clean and sometimes terrible.
there are so many open edges / overlapping faces and self intersections that the next workflow is not possible without manually correct each particle. i have more than 20.000 particle in this case, this is not a funny job.
i did many research, see many videos but nothing works. 
the example is very simple. 
i have a very clean source mesh without many issues and checked it with several tools.
1. birth the object
2. voronoi fracture (cap holes is activated, voronoi point type : on shape surface by tex ( texture of cracked stone ) )
3. subdivide
4. displace textmap  ( texture of cracked stone ) 

for the created particle next event
1. flock operator


tried physx shape, shell and many other operator . 

3d max scripting is no problem, but i don't have any idea to do something automatically.
for source mesh i tried quad remesher and so on in many variations.

does anyone have an idea what i can do ?