Ok, the thrips are gone, the next treatment can come in 2 weeks. I just topped the two larger plants again, but there was nothing to cut from the smaller ones.
Now I'm going to try the low-stress training and also put a scrog net at a height of 20 cm.
the weather is very hot, it's 30°C outside, the humidity in the tent is extremely high. my small dehumidifier does not do the job, I need to get a more efficient machine.