Wouldn't it be the same experience you get on a sunset flight followed by a sunrise flight? It's not like you'd see a spotlight of darkness, it's a gradient and likely too large to see moon curvature.

You're trying to conflate the sunset terminator vs the very small and well defined shadow of the moon itself. Totally different concepts. The shadow of the moon is a spotlight of darkness. This is so not the same thing as the Earth rotating out of view of the sun.

For example: https://image.pbs.org/poster_images/assets/buac18-vid-epicmo...

How is the edge of that shadow any less blurred than a sunrise or sunset?

For example, a normal sunrise you get on thousands of normal flights every day:

https://images.app.goo.gl/BHvD5aBSqkA9kT6C6