I’ve recently needed to create multiple extra variants of playback techniques. The purpose of this was to be able to select different unpitched percussion sounds playing the same type of technique for a little variation in playback (not differentiating the notation in the score). A simple example is the left and right stroke on a snare drum, but I was working with instruments that have 5, 10, or 20 variants of certain types of hits.
To accomplish this, I was duplicating playback techniques several times. To save time, I set the alias/fallback on a playback technique because I wanted them all to have the same alias/fallback. The alias/fallback is preserved after duplicating, but when I edit the name of the duplicate (I prefer a different format than “(2)”), the alias/fallback reverts to (Unset).