Refresh / Response Rate of the WYUR

With all the talk of the 'race mode' of the Wahoo Kickr and its increased 4Hz refresh rate

I'm wondering what is the response / refresh rate is of the WYUR when reading and retransmitting from a power meter (be it Ant+ or BLE) onwards to say Zwift.

Putting it another way, how much lag is induced by the WYUR instead of connecting directly