@mau_igna_06 it would be good if you could try the JointSmoothing option from the older ModelMaker. That mode was specifically added to provide watertight boundaries because the vertices of both models were moved identically during the smoothing process, so there was never any gap between the meshes for adjacent segments. There may still be some aspects of the older code that need to be incorporated in the segmentations infrastructure.
This topic has come up before, but it’s still not clear to me that we can easily get the same output meshes that we get with ModelMaker.