The easiest target is the google pixel 3 which is extremely oversaturated. It's tracking at $60-$100, which is still cheaper than slimevr and vive trackers, and likely only going to get lower.
The interesting part is that because its a pixel, even if it runs slow, OS suport.
So the idea comes from wanting to buy the cheapest phones with gyroscopes to accomplish fullbody VR tracking. After this, I'd create a cluster to use the devices as a combined supercomputer of sorts. Pooling resources together is a common practice in cloud computing.
The control script drives audio playing from a multiplexer mix with both tracks. There was a bug with starting multiple tracks, so a delay node was later implemented. There may be a bug with the track list not resetting, but that wouldnโt be too much of a hassle to fix.