Creating Basis Sketch preset directly from Song?

I don't know if this is possible and I haven't learned how to do it, or it does not yet exist.

I know if I import a SMF directly to a song it creates a Basis Sketch and if I save the song, it remembers that Basis Sketch. But that Basis Sketch is not yet a preset, it is only in the song as far as I can tell.

Let's say I only import 4 instruments from a SMF to a song and then select some replacements from my Basis Sketch presets, creating a novel Basis Sketch that I happen to like very much.

I would like to be able to immediately make a preset Basis Sketch from the instruments currently in a song.

Is this possible?

Prado