So I managed to dump the firmware off the old wemos and flash it to the new one using esptool.py

I also managed to eventually compile the code from GitHub with platformio after fixing a bunch of compiler warnings – noting the default is not a Smoggie PM like mine, but another sensor so I needed to adjust the configuration, and also reset the unique ID. There also seems to be issues with the serial port sending the Wifi commands over the serial port, as in there is no echo o response, which I’m also noticing with the V5 firmware not yet available on github?