The kickr is really giving you dual sided power, but it's merged together, obviously. I wonder if anyone has ever tried to deconvolve the data.
Wahoo would have to have a fairly complex extra circuit to determine which leg was which. Or a much more expensive crank with built in power meter. I can't imagine it's that important to too many people. The thing that's screwed up is the roam forcing you to use the one power stream instead of the other.