USR_DATA over MQTT

We are developing a mesh network system using DWM 1001.
I made a gateway using Raspberry Pi and exchanged communication between the server and the equipment through Mqtt’s Uplink and Downlink.
But originally, the number of data that the module can transmit at one time is 34 bytes, and is the communication speed slow, about 2-3 seconds?
The UWB introduction material says that it supports data communications of up to 27Mbps, but if the method I used is correct, it is too slow.

Please give me some advice.