Hi Gerald,
We have just received an explanation from the development. At the moment, when we pick up a parameter from an MEP element, it will use the group of Object. Because of this, you cannot set what kind of properties do you want to transfer.
We planned to enhance this, but there were some complications about the implementation. It turned out to be a big project-size task. I hope that we will be able to correct this in the future.
Thank you very much for pointing out the issue, and I am very sorry for the inconvenience! Please let me know if you have any further question!
Best regards,
Minh
Minh Nguyen
Technical Support Engineer
GRAPHISOFT