S2 app should allow saving of multiple Trueplay tunings. One benefit for this is that you can easily go back to a previous Trueplay configuration if your latest Trueplay tuning made the sound worse for your Sonos setup.
Also, with the reports that Trueplay gives different results depending on the iOS device you’ve used (e.g., https://www.reddit.com/r/sonos/comments/haxk68/sonos_arc_metallic_sound_sonos_community_please/fv7id97/), saved custom Trueplay profiles allow easy/swift comparison between two different tunings.