It really depends on the headset, but I think that most of current ones don't have a motion sensor, they are just located using either lighthouses, sensors or cameras. But you could still get the velocity from that. The bigger problem is that delay introduced and possible false positives and true negatives and that may lead to player's frustration. While I have lots of things that I want to add to the game, I will have to drop some ideas or at least leave them until an update.