Please extend the module by additional component - cloning content type definition of the node about to being converted.
So you have Node1 based on CType1, and the module first clones the content definition as CType2 and then converts Node1 into that type.
Scenario: You realize that for existing nodes you need a separate content type (Product display into Product display accessory) which would share most if not all of the fields. You want to easily convert one into another without having to painstakingly recreate all the fields in the new content type. So your first step would be to create the new content type.

The module should ask whether it should reuse the fields or create their clones as well, as this matters in some situations (more info on request). Or perhaps provide a form listing all fields about to be copied, where user could make a re-use/clone disposition.