Questions about data transmission in mesh networks, and measurement of packet loss rate and throughput in mesh .

Hi, all.

Q1:

      I have three nRF52840 boards and have been running the examples MESH and MESH-PROVISONER(nRF Connect SDK 2.1.2).One provisioner and two nodes.

In the mesh example, I'm attempting to modify the size of the buffer, as shown in the diagram below. When it's set to 32 bytes, the information can be transmitted successfully. However, when the length exceeds 32, it displays an error message in the serial information, saying "message too big." I'm wondering if there's a way to expand the size of the message.If I want to transmit a 256-byte data through the mesh network, how can I achieve that?

Q2:

Is there any way to test the throughput of the mesh network?

Q3:

When I use a button to control information transmission, such as pressing it once to send an "on/off" command to the target node along with a segment of data, I encounter the following err  when I quickly press the button twice (with an interval of less than 500ms), as shown in the diagram below. What could be the issue here? Is it possible to minimize this interval time as much as possible?

Q4:

I would like to test the packet loss rate of a mesh network at different speeds. How can I accomplish this?