I have tried the "DT Overlay" field as well as the "Named I2S Device" fields, neither will give me a I2S option in the Output dropdown. Here is the Startup Log with the Named I2S Device dropdown populated with my HIFIBerry card:
20241010 161854 worker: --
20241010 161854 worker: -- Start moOde 9 series
20241010 161854 worker: --
20241010 161854 worker: Successfully daemonized
20241010 161854 worker: Wait for Linux startup
20241010 161900 worker: Linux startup complete
20241010 161900 worker: Boot config is ok
20241010 161901 worker: Session loaded
20241010 161902 worker: Package locks applied
20241010 161903 worker: File check complete
20241010 161903 worker: Log to RAM on
20241010 161903 worker: Debug logging off
20241010 161903 worker: --
20241010 161903 worker: -- System
20241010 161903 worker: --
20241010 161904 worker: Host name: moode
20241010 161904 worker: RPi model: Pi-4B 1.4 4GB
20241010 161904 worker: moOde release: 9.1.2 2024-09-28
20241010 161904 worker: RaspiOS: 12.7 Bookworm 64-bit
20241010 161904 worker: Linux Kernel: 6.6.47 64-bit
20241010 161904 worker: MPD version: 0.23.14
20241010 161904 worker: User id: glenn
20241010 161904 worker: Home folder: /home/glenn
20241010 161904 worker: Time zone: America/New_York
20241010 161904 worker: Kbd layout: us
20241010 161904 worker: HDMI ports(s): on
20241010 161904 worker: HDMI-CEC: off
20241010 161905 worker: Sys LED0: on
20241010 161905 worker: Sys LED1: on
20241010 161905 worker: Reduce power: n/a
20241010 161905 worker: CPU governor: ondemand
20241010 161905 worker: Integ audio: vc4-kms-v3d
20241010 161905 worker: --
20241010 161905 worker: -- Network
20241010 161905 worker: --
20241010 161905 worker: Eth0
20241010 161905 worker: Ethernet: adapter exists
20241010 161905 worker: Ethernet: timeout off
20241010 161905 worker: Ethernet: method dhcp
20241010 161905 worker: Ethernet: address 192.168.1.24
20241010 161905 worker: Ethernet: netmask 255.255.255.0
20241010 161905 worker: Ethernet: gateway 192.168.1.1
20241010 161905 worker: Ethernet: pri DNS 192.168.1.1
20241010 161905 worker: Ethernet: domain none found
20241010 161905 worker: Wlan0
20241010 161905 worker: Wireless: adapter exists
20241010 161905 worker: Wireless: country US
20241010 161905 worker: Wireless: SSID None
20241010 161905 worker: Wireless: other None
20241010 161905 worker: --
20241010 161905 worker: -- File sharing
20241010 161905 worker: --
20241010 161905 worker: SMB file sharing: off
20241010 161905 worker: NFS file sharing: off
20241010 161905 worker: DLNA file sharing: off
20241010 161905 worker: --
20241010 161905 worker: -- Special configs
20241010 161905 worker: --
20241010 161905 worker: Plexamp: not installed
20241010 161905 worker: RoonBridge: not installed
20241010 161905 worker: Allo Piano 2.1: not detected
20241010 161905 worker: Allo Boss 2: not detected, OLED script ok
20241010 161905 worker: IQaudIO AMP*: not detected
20241010 161905 worker: --
20241010 161905 worker: -- ALSA debug
20241010 161905 worker: --
20241010 161905 worker: Cards: 0:vc4hdmi0 1:vc4hdmi1 2:empty 3:empty
20241010 161905 worker: 4:empty 5:empty 6:empty 7:empty
20241010 161905 worker: Mixers: 0:none 1:none 2:none 3:none
20241010 161905 worker: 4:none 5:none 6:none 7:none
20241010 161905 worker: --
20241010 161905 worker: -- Audio configuration
20241010 161905 worker: --
20241010 161905 worker: Audio device: 0
i HDMI 1
20241010 161905 worker: ALSA card: has not been reassigned
20241010 161906 worker: MPD config: updated (iec958 device)
20241010 161906 worker: ALSA output: HDMI
20241010 161906 worker: ALSA mode: IEC958 (iec958)
20241010 161906 worker: ALSA mixer PCM
20241010 161909 worker: ALSA volume: controller not detected
20241010 161909 worker: ALSA maxvol: 100%
20241010 161909 worker: ALSA loopback: off
20241010 161909 worker: MPD mixer Software
20241010 161909 worker: Audio formats: Alsacap was unable to detect formats
20241010 161909 worker: CamillaDSP: off
20241010 161909 worker: CDSP volume: 0dB
20241010 161909 worker: CDSP volrange: 60dB
20241010 161909 worker: --
20241010 161909 worker: -- MPD startup
20241010 161909 worker: --
20241010 161909 worker: MPD service: started
20241010 161909 worker: MPD port 6600: accepting connections
20241010 161910 worker: MPD ALSA Default: on
20241010 161910 worker: MPD ALSA Bluetooth: off
20241010 161910 worker: MPD HTTP Server: off
20241010 161910 worker: MPD volume: 0
20241010 161910 worker: Saved MPD vol: -1
20241010 161910 worker: Saved SRC vol: 0
20241010 161910 worker: MPD crossfade: off
20241010 161910 worker: MPD ignore CUE: no
20241010 161910 worker: MPD CDSP volsync: off
20241010 161910 worker: --
20241010 161910 worker: -- Music sources
20241010 161910 worker: --
20241010 161910 worker: USB drives: none
20241010 161910 worker: NVMe drives: none
20241010 161910 worker: NAS sources: none
20241010 161910 worker: --
20241010 161910 worker: -- Feature availability
20241010 161910 worker: --
20241010 161910 worker: Input select: available, Source: MPD, Output: Pi HDMI 1
20241010 161910 worker: Bluetooth: available, PIN: None, ALSA/CDSP maxvol: 100%/0dB, ALSA outmode: Standard
20241010 161910 worker: AirPlay: available
20241010 161910 worker: Spotify Connect: started
20241010 161910 worker: Squeezelite: available
20241010 161910 worker: UPnP client: started
20241010 161910 worker: Plexamp: not installed, ALSA maxvol: 100%
20241010 161910 worker: RoonBridge: not installed
20241010 161910 worker: Multiroom: available
20241010 161910 worker: GPIO buttons: available
20241010 161910 worker: Stream recorder: n/a
20241010 161910 worker: --
20241010 161910 worker: -- Security
20241010 161910 worker: --
20241010 161910 worker: Web SSH server: off
20241010 161910 worker: XSS detection: off
20241010 161910 worker: HTTPS mode: available
20241010 161910 worker: --
20241010 161910 worker: -- Peripherals
20241010 161910 worker: --
20241010 161912 worker: Local display: off
20241010 161912 worker: HDMI 4K 60Hz: off
20241010 161912 worker: On-screen kbd: off
20241010 161912 worker: Rotary encoder: off
20241010 161912 worker: USB volume knob: off
20241010 161912 worker: LCD updater: off
20241010 161912 worker: --
20241010 161912 worker: -- Miscellaneous
20241010 161912 worker: --
20241010 161912 worker: Software update: Automatic check on
20241010 161912 worker: Software update: Checking for available update...
20241010 161912 worker: Software update: Software is up to date
20241010 161912 worker: Auto-CoverView: off
20241010 161912 worker: CoverView timeout: Never
20241010 161912 worker: Auto-shuffle: off
20241010 161912 worker: Auto-play: off
20241010 161912 worker: Maintenance task: 360 mins
20241010 161912 worker: Current view: reset to Playback
20241010 161912 worker: Active flags: all false
20241010 161912 worker: Reset flags: skipped
20241010 161912 worker: Session check: ok
20241010 161912 worker: --
20241010 161912 worker: -- Startup complete
20241010 161912 worker: --
20241010 161912 worker: Mount monitor: started
20241010 161912 worker: Radio monitor: off
20241010 161913 worker: Watchdog monitor: started
20241010 161913 worker: Responsiveness: Default
20241010 161913 worker: Ready