On a AMW037 module, how much delay is necessary between issuing a write command before the data can be sent over a TCP Client to a host?
No specific answer here, as it depends on the packet size and medium congestion and remote acknowledgement. What I need to highlight here is that you should not worry about that. The device TCP stack will handle that internally, as long as flow control is enabled. So, please make sure you have uart.flow is enabled, then send on your maximum speed. The UART will instruct the host to stop sending if the internal buffers are full and data is not sent to the remote yet. Also please make sure your host is following the RTS/CTS flow control protocol.
To enable flow control, please set uart.flow to 1