Bluetooth headset in desktop mode: how to?

[deepfire]

Your system information

• Steam client version: unrelated
• SteamOS version: Brewmaster 2.195
• Opted into Steam client beta?: Yes
• Opted into SteamOS beta?: Yes
• Have you checked for updates in Settings > System?: Yes

Please describe your issue in as much detail as possible:

One would like to use a bluetooth headset in desktop mode -- both for application audio, and games launched from the desktop Steam client.

It is currently unclear if this is possible at all.