The 6.6.3 update was largely a "maintenance" release that addressed critical performance bugs, particularly for users on newer hardware:
This allows for library management across up to 8 devices , ensuring your playlists, Hot Cues, and loops are synced between your studio PC, mobile app, and performance laptop. Pioneer DJ Rekordbox 6 Professional 2022 6.6.3
Resolved a notable crash on Mac computers using the Apple M1 chip when switching the JOG display to "Hot Cue Countdown". ensuring your playlists
Included access to Video, Lyric, and RMX effects, as well as Vocal Position Detection , which visually displays where vocals are in a track to avoid clashing during mixes. Core Ecosystem Features and RMX effects