I found out why the first round of edits seemed really light

It turns out that the technical editor doesn't look at how badly I've written things, but instead looks at the content and form of the chapters. Now that I've made it to the copy editing stage, I feel quite a bit better knowing that my writing has gone through both steps. All of the pages I've gone through so far have as many edits as shown below:

Making my way through the edits and waiting for permission to come back from the places owning things of which I took screenshots for the book...