It would be a bit more problematic, mainly because during the import we are partitioning and formatting data into structures suitable for fast local access by the world renderer, stripping unnecessary attributes in the process. OT isn't using typical GIS data internally, as these aren't the most suitable formats for a (procedural) world rendering engine, but it would be theoretically possible to capture the generated output and export data that way. However, this usage is rare, and the required effort probably would not be justified ...
