To allow for higher information density, there could be a toggle to enable minification which could temporarily remove all newline characters.
To nudge users back to the normal state, this would not be persistent, so when you visit a new page the minification will be turned back off. For those who wish for it to be a permanent thing, perhaps it could be in settings.
In code, minification removes all whitespace characters. WeWrite will have a different take, we'll keep whitespace (so that things remain readable) but all newline characters will be removed, thus butting paragraphs up against one another.
Most readers will probably enjoy having spacing, but for the readers who are insane, they'd prefer to consume a block of uninterrupted text. Minified mode is for those insane readers.
Perhaps this mode could be activated by double tapping the zone near a period?