Question about BenQ Screenbar

I suspect NO. This screenbar is perfectly matched to the BenQ and scatters absolutely no light onto the screen. This would be lost with a curvature. You would have to construct something yourself.

Philipp Rüegg, who wrote the article on the Screenbar (linked on the product page), replied to a comment that he had tested it with a curved display.
A quick measurement with a ruler showed that the lamp is about 1.5cm in front of the screen at a distance of 25cm from the centre (without Curve) - but at a height that the screen would theoretically fit underneath. The beam angle sideways is relatively large, but the 1.5 cm distance to the screen will certainly not be less downwards. I hope you can do something with this information.

I have mounted the screenbar on a 27 inch BenQ screen. The screenbar stands approx. 2 cm in front of the upper edge of the screen and can be rotated by approx. 10 degrees in the socket. When the direction of light is turned away from the screen, the limit of the illuminated area is approx. 5-6 cm in front of the lower edge of the screen. If the curvature of the screen does not exceed this 5-6 cm margin, the screen should remain outside the directly illuminated area.

it works also have it on curved monitor

Yes is possible. I have mounted it on my Dell 38 inch monitor (Dell UltraSharp U3818DW). It is also wider at the top than the specified maximum of 3 cm. Nevertheless, the screen bar fits perfectly and I don't want to do without it.