Hello, I have a Dell C3422WE (also 34", but "only 7.30 kg): The holder holds, but I had to tighten the tension spring quite a bit.
The holder can support the 9.4 kg. However, you lose the advantage of the height adjustment: you will always have the monitor at the lowest point. You'll have to decide for yourself whether that suits you...

Hi, I have two 34 inch monitors and I have no problems at all, I think you can do it with ease, the product is top, it has excellent mobility, I am mega satisfied.