Hi Karsten, yes that's true that Solids++ is able to represent a non-manifold edge if desired and things like the booleans will use that during part of its data processing, but after the boolean calculation is completed MoI will decompose objects into manifold volumes and only put manifold objects into its own geometry database.

There are a lot of various difficulties with trying to work with non-manifold structures as a regular runtime object representation, things like import/export to other CAD systems, and other operations like filleting are not expecting to work with them.

- Michael