By the evening, I powered the quad in the garden and finally get the DIY IR illuminator module airborne. A LOS flight by the evening in rate mode is not the best, sometimes I thougtht I lost the oriantation at all
The quad AUW is now 600g, the flight was only 02:20 long. Charged back 400mAh into the battery.
After the landing, I checked the module temperature and it was really warm but not too hot to touch, so my assumption about airflow cooling was right. The concept seems to be working. Now I am waiting for the IR sensitive FPV camera, to be able to test the quad in the field.