Well I can't recommend trying this as it bricked our RN2483...
Initial connection is fine with serial forwarding, all commands go well and get a response.
I then tried to update the firmware, the DFU console showed sys erase fw and then uploading firmware, at which point I wanted to resize that part of the window, and it closed everything to the startup state...
If I set to bootloader mode, I can select the file and start update but it just closes everything again after a while.
BTW I saw in the end of your text you say 19200 as the rate but in the documentation it is 57600 in all sections.