> \s[-X]\H[+X]text to be kerned goes here\H[0]\s0
I believe distorting the shapes of letters is even more frowned upon in typesetting circles than consecutive hyphenation is. As a practical approach to manually optimizing the line breaks in a paragraph, I have found that twiddling the space size using .ss often leads to acceptable results. Also, using \p (or .brp) to break-and-stretch a line earlier in a paragraph can sometimes lead to nicer line breaks later on in the paragraph.
