i don’t have an answer to your question, but it looks you plan using the device for a different purpose than just meteo data.
I’m not sure the instrument is using an instant measurement. Let me tell you again, I don’t know, but it might be that in order to get one speed/direction value ready to be send to the hub, it could do several intermediate ultrasound measurements between pairs of transducers. Those measurements take time. probably more time then any latency the udp creates. So the value you get might be from an average over a small period. It might even be that the assumption is that the wind is rather stable between intermediate measurements (which might not be the case, for whatever you are trying to measure).
In other words, depending on what you really want to measure with the unit, you better know a bit more about the unit itself before starting to wonder what udp latency might be.