Yes, it is from the second video that @jeffb posted, Flood Expert Gives 5 Evidences For a Global Flood, which has “Their great extent, their flatness, and their lack of erosion” as a subsection-title. Here is an AI-generated transcript of the “Plateau” section:
So you mentioned plateaus to start with. Now, can you tell us what is a plateau? - Well, a plateau is a sort of an elevated, fairly uniform surface. It’s often called a tableland by people, and it’s often dissected by steep gorges or steep cliffs, so on, around them, or through them and so on. Plateaus can be thousands of square kilometers in size, actually. - Okay, and so, how do plateaus indicate a flood occurred in the past? - I guess there’s three points I’d like to make on that. Firstly, plateaus are very common. 70% at least, possibly even up to 75% of the planet, is covered in sedimentary rock, of which 40% of all of that is a plateau. Even in places like Africa, it’s 60% of the entire continent is a plateau. That’s the first point that I’d like to make. Secondly, the elevated plateaus seem to lack the evidence of erosion that would’ve occurred over millions of years. You’d expect to find a far more undulating terrain. And yes, there are some small undulations, but over hundreds of millions of years, these plateaus at times retain an incredible consistency in all of that. The third point is that’s despite the fact that in sometimes the sedimentary layers are not horizontal, they’re are actually tilted, so they’ll actually tilt upwards or in different angles and so on. And so sometimes there’s hard rocks tilted up and next to 'em are soft rocks tilted up, yet the erosion across the top or the plateauing is uniform, or equivalent. In other words, you would expect over millions of years that the softer rocks would’ve eroded out, leaving the harder ones as cliff faces and all sorts of things. So I think those three lines of evidence point to fact they’re quite young. - Got you. So you’re saying that there’s a large extent of plateaus, so there’s a lot of them, we need to explain them. And then you should have undulations. - Absolutely. - But you’re saying because they’re flat, it’s showing you that the millions of years is not necessarily true. - That those plateaus are recent features, recently created. - So you said, “Okay, this flood occurred recently.” So why do they tell us that a flood’s happened? Like, what forms the plateau? - Well, it’s sedimentary rock. In other words, it’s actually primarily made up of flood sediments. In other words, you can have landslide sediments and medial sediments and all those, but plateaus around the world are made up of flood sediments. And the fact that a plateau might occupy 10,000 square kilometers says (laughs) that’s a pretty large flood. - And the way they’d form is by planation, right? It’ll be like a planation surface, they’re sometimes called, is that right? - That’s correct, yes. Although planation has a slightly broader meaning than that, but yes, you are correct that plateaus are part of planation surfaces. - So speaking of a big flood, that the runoff in the flood has caused it to be eroded flat. - Yes, that’s why you’ll often see one plateau sitting on another plateau where the one on top is slightly more dissected than the one underneath. It’s rather fascinating when you look at those plateau on plateaus.
Neller would seem to fail to even mention any of these issues (or the issues I raised in the post you are replying to).
This of course leaves his claims “not properly filled out or developed” – i.e. vacuous, and so of zero evidentiary value.
It is possible that Neller has developed this claim elsewhere, but that Jeff has simply failed to bring it to our attention. Jeff does however seem to be fairly insistent that we should be basing our understanding on these videos:
It is also possible that as a fluvial geomorphologist and “flood expert”, these issues simply lie outside Neller’s field of expertise.
As the saying goes:
If all you have is a hammer, everything looks like a nail
And Neller may simply lack the tools to properly analyse if things-that’re-not-a-flood could cause the features under discussion.