What's cool with those models is that you can tweak the thinking process, all the way down to "no thinking". It's maybe not available in your inference engine though
FWIW, their readme states /nothink - and that's what works for me.
>/think and /nothink instructions: Use those words in the system or user message to signify whether Qwen3 should think. In multi-turn conversations, the latest instruction is followed.
Turns out just is not the word here. My benchmark is made using conversations, where there is a SystemMessage and some structured content in a UserMessage.
But Qwen3 seems to ignore /no_think when appended to the SystemMessage. I can try to add it to the structured content but that will be a bit weird. Would have been better to have a "think" parameter like temperature.