If you mean SpeedFlex, you're sending the maximum packets (TCP or UDP) between 1 client and the ZD, thru the AP (and maybe mesh chain behind it) that the client is connected to. TCP reliable delivery, UDP best effort. Is that what you are asking?
Yes, speed flex results when run in TCP and UDP...also it is seen that speed flex results done in UDP are sometimes misguiding!! for example if we run speedtest in tcp result shows 15Mbps and in UdP shows 45Mbps ...which one is reliable speedtest and why its varying between tcp and udp, then what its difference...