The phrases are not meant to be used as an alternative to an arpegiator, but more as a replacement pattern to be played where normally a step would be played. The step ‘triggers’ the pattern.
This way you can run at a relaxed tempo where each step represents a 16th of a bar, and have a step trigger a pattern of 32nd notes.
It’s probably even possible to combine the pattern with the random note pool feature and have the pattern play partly.