How to disable flags SERIAL_AUTO_TRANSMIT and SERIAL_AUTO_RECEIVE using boost asio

I am working with an RS485 device and I need to change its transmissions FlowReplace property from 0x43 to 0x40. Here is my Eltima Serial Port Monitor log.

Currently it is:

47 IRP_MJ_DEVICE_CONTROL - Request operates a serial port (COM3) 
    STATUS_SUCCESS 
        IOCTL_SERIAL_GET_HANDFLOW - Request returns information about the configuration of the handshake flow control set for a COM port 
            ControlHandShake - 0x01 (SERIAL_DTR_CONTROL) 
            FlowReplace      - 0x43 (SERIAL_AUTO_TRANSMIT | SERIAL_AUTO_RECEIVE | SERIAL_RTS_CONTROL) 
            XonLimit         - 0 
            XoffLimit        - 32768 

But it must be like this:

64 IRP_MJ_DEVICE_CONTROL - Request operates a serial port (COM3) 
    STATUS_SUCCESS 
        IOCTL_SERIAL_GET_HANDFLOW - Request returns information about the configuration of the handshake flow control set for a COM port 
            ControlHandShake - 0x01 (SERIAL_DTR_CONTROL) 
            FlowReplace      - 0x40 (SERIAL_RTS_CONTROL) 
            XonLimit         - 0 
            XoffLimit        - 32768 

The difference between FlowReplace 0x43 and 0x40 is in these two flags SERIAL_AUTO_TRANSMIT and SERIAL_AUTO_RECEIVE.

I probably could achieve this by configuring the _SERIAL_HANDFLOW structure, but I'd like to have a cross platform solution, unless there is no other way.

So, is there any way to fix it without calling a native handle? I sadly can't find anything here: https://www.boost.org/doc/libs/1_64_0/boost/asio/serial_port_base.hpp