That’s not an approach I considered taking when constructing the tutorial. It sounds really interesting if it eliminates the need the pile of delegate code required to reconstruct/deconstruct the navigation stacks during trait change.
Im guessing you mean place the folder list (and file list in sub-secondary) in their own split and place that in the primary while the placeholder/editor remains within the main secondary.
I love it when people come up with new ideas for things. Thanks for the suggestion. Id like to see the result if you ever write the tutorial.