Hi @smeer,
I tried your solution B and got it partially working. The controllers are correctly tracked and can be seen in the headset, yet the position and rotation of the headset isn't tracked. We use this setup:
Vive Focus 3
Vive Wave XR Plugin 4.1.1
Input System 1.0.2
Unity 2020.3 LTS
XR Interaction Toolkit
WaveDeviceLayouts.cs from github
The scene contains a simple action-based XR Rig that just works fine with an Oculus Quest 2. Do you have an idea why the headset is not tracked?