Quote - I found out there is a problem with the displacement: it makes my model to
"explode"  at the edges. I think there must be a simple solution by combining some math nodes,
but I was not successful yet.

While not theoretically impossible to correct with nodes, doing so would be far more work than making the geometry compatible with displacement.

What you need to do is weld the vertices and then use some modelling program to (micro) bevel the edges.

The reason this is necessary is that Poser will only displace surfaces along the normal, so unless the displacement is zero, sharp edges will always split.