SteelSeries GameDAC does not use 24-bit audio streams

When playing audio on a SteelSeries GameDAC hardware device, the audio stream going into the hardware is always 16-bit even though it supports 24-bit audio. This can be seen on the device itself; it reports the audio stream it's currently playing.

Hardware stream info from /proc/asound/card#/stream0 (I can report more info if needed):

SteelSeries SteelSeries GameDAC at usb-0000:00:14.0-9.2, full speed : USB Audio

Playback:
Status: Running
    Interface = 2
    Altset = 1
    Packet Size = 288
    Momentary freq = 48000 Hz (0x30.0000)
Interface 2
    Altset 1
    Format: S16_LE
    Channels: 2
    Endpoint: 1 OUT (ADAPTIVE)
    Rates: 44100, 48000, 96000
    Bits: 16
    Channel map: FL FR
Interface 2
    Altset 2
    Format: S24_3LE
    Channels: 2
    Endpoint: 1 OUT (ADAPTIVE)
    Rates: 44100, 48000, 96000
    Bits: 24
    Channel map: FL FR

Capture:
Status: Stop
Interface 1
    Altset 1
    Format: S16_LE
    Channels: 1
    Endpoint: 1 IN (ADAPTIVE)
    Rates: 96000
    Bits: 16
    Channel map: MONO

This setup worked before in Pulseaudio by configuring it to use s24le audio.