I have the same observation — it is very bad at low-power heating and never drops below 600W. It appears to quickly heat up the air and modulate rapidly as it reaches the low and high threshold temperatures.

I was hoping that connecting the XK76 controller would make it use its sensor for the room temperature but it doesn’t appear to be happening, and I can’t really move the built-in temperature sensor to a different location.

I could try using the remote with the “I-feel” mode as it would then send the temperature readings from the remote. Will report back if I see an improved behaviour.