Igor, you raise an interesting question with this issue. When shooting in the field I try to leave blue space around singular clouds where possible. In fact in this recent post of mine, I got a suggestion for rework along those lines, and I think cropping to remove a clipped cloud helped
In @Dave_Dillemuth image here, the clouds did not bother me at first, but after seeing your comment/question, I can see the point you are raising about the cloud in the ULC. I think there are two things about it that make me pause a little.
First the cloud goes right out of the corner of the frame, and lines leading out to corners can sometimes bother me. This issue sounds like it is related to your concern. Second, to me the ULC cloud feels like it has a lot more visual weight than the clouds in the center, so some folks could argue that is unbalanced (some might not). This issue is probably not related to your concern. In Dave’s image, these things are not a major concern to me, but perhaps a very slight crop from the top would help mitigate these concerns.
However, in general, I think you raise a valid issue. In most cases I like to leave some breathing room around important compositional elements, such as clouds. So it’s something to be aware of and think about, I think it often will make sense to do, and it leaves leeway for cropping too.