That's kinda complicated story. Speaking very short - we (Senso Devices) developed our own tracking technology (Gloves + Haptic suit + Optical cameras) : https://www.youtube.com/watch?v=gMsDHbxtjHw and started separate project to utilize and popularize this technology - sfera.one - https://sfera.one/en We use wearable PCs (backpacks) and develop our own VR content for this. Its absolutely freeroam, no wires, walking area is around 100m2. We track whole body (actualy I believe sfera.one is the only park in the world to have actual body tracking, tracking all joints and even hands and fingers (and not IK by few spots). So the movement looks very natural. We also use Senso Gloves to have haptic feedback from VR. We currently have two spots in Russia, raised some investments to scale to China market and were opening our first spot in Shenzhen in February, when this coronavirus thing started. So now the project is paused, I wait while I can travel back to China and go on :)
That's in short - feel free to ask if any specific thing is interesting to you!