Yes. The effect of wind blowing normal to the sonic path on the speed of sound (sonic temperature) is corrected for in the CSAT3 electronics. The corrections to the speed of sound (sonic temperature) described in
Liu, H., Peters, G., and Foken, T.: 2001, “New Equations for Sonic Temperature Variance and Buoyancy Heat Flux with an Omnidirectional Sonic Anemometer”, Boundary-Layer Meteorol., 100, 459-468.
Schotanus, P., Nieuwstadt, F. T. M., and de Bruin, H. A. R.: 1983, “Temperature Measurement with a Sonic Anemometer and its Application to Heat and Moisture Fluxes”, Boundary-Layer Meteorol., 26, 81-93.
need not be applied to CSAT3 speed of sound (sonic temperature) data.