Hi
It seems that the exporting or importing of tempo maps (operation manual page 908) is broken.
You can export a tempo map to a .smt file, but it’s file icon is a plain document - as if it’s unrecognisable.
The file might actually be OK, but Cubase won’t let you import it into another session - it won’t let you choose it in the import dialogue box.
So wether it’s a broken exported file, or an importing issue is not clear.