Fixed

Migration: Empty collections should no longer be saved to disk
Song select: Prevent out-of-view groups to block visible ones
Song select: Selecting a group now immediately saves the selected group for the next launch
Song select: Group selection dropdown no longer shows less items than the full height when opened for the first time
Audio system: Skip buffering for gameplay audio
Gameplay: Speed mod override should be turned off after exiting from practice mode

Improved