Yeah, but if you steel-man it,

The act of steelmanning means to argue against a different position then the one the person is holding. It very worthwhile to criticize people for holding positions for the wrong reasons.

I think he was trying to make something similar to a map-territory distinction. It's often useful to make a distinction between the data and our best interpretation of the data. Some conclusions don't require much extrapolation, but others require a great deal.

To me what you are saying doesn't seem like a description of the map-territory distinction. A map is not an extrapolation of the territory but an abstraction of it.

If things are "open questions" until they are above a confidence interval of, say, 0.99

That sentence doesn't look to me like it's inspired by looking at what scientists do. I'm not aware of a scientific community having the standard of question being closed when they are over a confidence interval of 0.99.

You might argue that scientists should do things that way, but that doesn't have much to do with the question of how scientists act in the real world.

It's often useful to make a distinction between the data and our best interpretation of the data.

Statements about what's useful are different than statements that describe what scientists do in reality.

Using a historical example which happens to be false just complicates things. If I recall, philosophers first hypothesized a round earth around 600 BCE, but didn't prove it experimentally until 300 BCE.

I think you missed a point. At 300 BCE they were not centrally concerned with proving via experiment that the earths is round. They instead cared about things making sense intuitively. The idea that it's important to prove claims via experiment came with Descartes into the scientific mosaic which happened much later.

Nobody at the time between 600 BCE and 300 BCE said: “The part of the Earth that I can see at any given time appears to be flat, which would be the case when looking at a small piece of many differently shaped objects up close, so I don’t have enough information to know what the shape of the Earth is. One reasonable hypothesis is that the Earth is flat, but until we have tools and techniques that can be used to prove or disprove that hypothesis, it is an open question.”

If things are "open questions" until they are above a confidence interval of, say, 0.99, then just about everything we discuss here is an open question, as the quote suggests.

"How does action at a distance work?" wasn't an open question shortly after Descartes. It became again an open question when Newton was shown to be right by the expedition that measured the shape of the earth.

In biology the central dogma of molecular biology was considered a close question for a long time. Biologists where confident about the fact that a lot of the DNA is junk DNA that doesn't do anything.

One of the main reasons why we don't consider the question of whether homeopathy works an open question isn't just that we lack empiric evidence for it working but that we based on our theories of chemistry we don't believe that it could work.

Whether or not chiropratics interventions work was a question that scientists considered not to be open for a long time.