Thanks for weighing in; please see my response to chrillek, I hope that clarifies that I am, I think, taking the simplest approach possible, but why still “it’s complicated.” Apologies if I am overlooking something.
A while back when DT3 arrived, I worked really hard in the forum to clarify my problems with the disappearance of three-pane view. After describing, with quite a few others, at considerable length how that interface change was hampering my work, new capabilities were added to the sidebar that solved the problem. Very grateful for that! There are a number of us now who’ve been trying to describe our wishes for the visual experience of the text editor window in DT. The OP’s points above about column width and white space get to the core of the problem for me, and the screen shots demonstrate the problem well. If there was simply a way for us to adjust the default column width and the vertical spacing between lines in the text editor view, on both the computer and the iPad, it would be a vast improvement.
I say all of this as a huge, huge fan of DT as a general tool for writers—I have been using it for many years and recommend it to everyone—and I recognize that there is an aesthetic element to creative production that I’m describing that may not be relevant to others.