In reply to An Ideal Page: Line length, Leading, Margins, Page Size, Etc.:
Optimal line length depends on layout.
Longer line lengths are slower if they increase the possibility of going astray between lines.
If there is more leading, or paragraphs with fewer lines, that likelihood decreases.
A page layout of really long lines, separated into three-line paragraphs, would, I predict, read very quickly.
In particular, the reader would pick up considerable speed along the straights, before going into the hairpins.
Page-width decks of 100+ characters, three or four lines deep, are quite manageable.
