Hi,
I have the same problem with clouds in OpenGL but not with the planes... I have texture flickering on the ground and forest. It's why I play in DirectX mode, but I think it's because you don't have a great graphic card or Il2 1946 doesn't support laptop card.
I run Il2 1946 on laptop too
---> Intel HD Graphics lol
I hope Daidalos will make a patch for laptop support.