This is not possible. Convergent bodies are not b-rep bodies, they are a new type of object called a Parasolid Mesh which is basically facet based. Export to Parasolid or STP require a b-rep solid or sheet body.
I had the same question not so long ago.
File an ER. There is anexisting ER for this; ER 8986996. Add your name to it.
Maybe something will happen faster.