The ESP32 has a built in infrared decoder/encoder, I wonder if you could just skip the intended IR LED that it's supposed to drive and just wire it directly to the receiver pins on the target device with an appropriate resistor. That's the same thing going on here except using the PIO (which was cool to see explained and makes me want to play with the 2040W) and I have an air purifier I kinda want to smarten up...