I would prefer that view settings were retained by the window rather than by individual book.
When I am reading a Bible, and change to a different Bible using the arrow keys, it would be preferable if the next Bible is shown with the same settings (excepting impossibilities like missing interlinear, etc.), so that the displayed text of the next Bible is shown in the same format as the previous Bible (like moving to the next record in a database) instead of restoring the settings that were used the last time I opened that Bible.
For example, last time I used a Bible, I might've been diving deep with an interlinear, but today I am looking for surface-level text comparison.
Also, I recently discovered the useful Text Comparison tool. The Interlinear mode is neat when it (rarely) works (unfortunately, it usually says "There are no results for this reference in the selected books.").