If the Zwift VR beta never made it due to concerns regarding the build up of sweat etc, then why not use a webcam to enable head tracking in Zwift.
This feature is used extensively in online SIM racing such as iracing and assesto Corsa and gives you the ability to look to your left and right and even behind you in some cases.
Most people have a webcam and would bring additional immersion at little to no costs to the subscriber.
Just search on YouTube for free head tracker in SIM racing and you can see many examples of how this works.