Transforming/embellishing melody

I've imported a midi file with a simple/sparse melody and am wondering what my function options are for adding density/embellishment that replaces some of the rests? If I use the density or pitch-ornament/pitch-figurate functions, they add material around each note but they preserve the rests. Is there another option that would replace some of the rests with generated material? Or would the right approach be to generate material separately and insert it into the positions where the rests are?

The imported omn looks like :

(e cs6 fff -he e c6 mf -q. e fs5 fff -q. e d6 mf - -q. e g6 -he e ds6 -h. - e fs5 -q e d6 -q. e as4 -q -h -e fs6)