[member="Kami Meran"]
What brought you to the ideal that Song steel would only be good in a rapier style blade?
On regards to Beskar: via some techniques, one could make a pure Beskar sword that would be light as titanium equivalents. So it could be used for basically anything. That is true.
However, as said, an ideal bladed weapon will be backed with heavy velocities, which are best reached by weight behind it. So all in all, while either would make a good weapon, I agree to the aforementioned - double layer, Beskar out Song in, and I would also add twice tempering as well alongside a freeze bath to allow the blade to harden as well as it would be able.