Better since you can use partial bars for this. So, you can change the volume in beat 2.5 of the current bar and then restore it at beat 1.854 2 bars later
The reason I did this was to handle a fermata better in a song I was playing. I wanted the guitar arpeggio to play slowly on a single, paused beat so I found I needed to use truncate before and after and it just got ugly. This works much nicer