Toggling Settings > Appearance > Use compact room list does not change the density of the room list, it just toggles the visibility of recent messages in the room.
Can confirm. Although it does change after you restart the app or you change something else afterwards like change room list sort order. Operating System: Arch Linux Neochat: 24.08.1 KDE Plasma Version: 6.1.5 KDE Frameworks Version: 6.6.0 Qt Version: 6.7.3 Kernel Version: 6.10.10-arch1-1 (64-bit) Graphics Platform: Wayland