Tundra Tracker Support for Rift S, Reverb G2, Quest, Quest 2?

This answer is much more nuanced. Like we said above, the key infrastructure for Tundra Tracker is SteamVR and SteamVR Tracking (aka Lighthouse). There is some very interesting work, especially done by the OpenVR Space Calibrator community to use SteamVR's extensibility to merge the coordinate spaces of these SLAM tracked headsets.

To do this, you must acquire either Gen 1.0 Basestations from HTC or Gen 2.0 Basestations from Valve. These basestations will not be included with Tundra Tracker.

After you have Basestations, there are further software steps to set things up and calibrate the space. The process cannot be called "easy" or "plug and play" today but the community is working hard on improving and more video tutorial content is emerging. Unfortunately Tundra Labs cannot directly support you though this calibration process but the community appears very helpful.