Seems like ODA Teigha BIM API has led to a number of BIM apps offering a RVT importing facility. Launched back in 2016.
1. Vectorworks. An early adopter, but with a lot of problems.
2. ArchiCAD thru BIM6x
3. BricsCAD
4. ITC IntelliCAD 9 will supposed support RVT as underlays.
5. Graebert Kudo
It would be good to enhance the current ISM / i.Model publisher plugins to translate 2d information as well as architectural and MEP elements.
Referencing (like IFC) would also be great but I see ISM being the mode of choice.
With the iModel technology and using connectors to bring various data to an iModel which can then be referenced, if needed into MicroStation or any other Open Bentley products.