Heres a video of it making its first cut. https://www.youtube.com/watch?v=jx7bP04f8M8
Here is a less loud video made by google of my assorted images/videos https://www.youtube.com/watch?v=0bFK9dD4zVo
At 4ftx4ft do you see any flex? I don’t see any supports mid span.
Flex doesn’t seem to be an issue. I am quite happy with its performance
Is your over all dimensions 4x4 or is that your cut dimensions?