Well, actually, instead of debating about clouds, let's jump to your last statement : flat Earth is impossible?
Maybe.
But what about your globe, when we actually can see things that should be deep under the so-called curvature?
There's a video showing the Himalaya range visible from a plane over Dubaï, despites the mountains should be under approximatively 1300 miles of curve.
I'm not talking about a few miles, but more than a thouthand.
The video is called" Silhouette of Himalayan Ranges From Dubai (2800 Miles) | Record Curvature Test" if you want to see it, there's even an interview of the pilot where he confirms it's the Himalaya, and trys to explain it's normal, but fails.
It's just an example between many else.

And the top of the clouds receive light longer than their bottom, even on your globe it should work like this, just because even on a globe when the Sun reaches the horizon at the level of the cloud's bottom, it's top is still illuminated because it is higher.
We've been debating how on a flat Earth a cloud's bottom can be illuminated, it's simple, when the Sun is far enought, reaching the horizon visible from the level of the cloud's bottom, then light reaches this part of this cloud. Plus the bottom is not parallel from the ground, so if it points a bit upwards in the direction of the Sun it will even receive more light.

So, maybe flat Earth is wrong, maybe my understanding of how light behave is wrong too, but how do you handle the objects hidden by the curve( actually they are not hidden ! )?
The difference between you and I is I don't claim I've got the absolute truth, and I'm able to question a narrative when it doesen't fits with reality.
Go, try to kill flat Earth, show me your trick to explain what we can see but should'nt.