I'm not sure why the Jquery version allows negative letter spacing yet the WordPress version of FPD doesn't... but as a designer Im shocked this is not a standard feature.! I kern practically every line of type I set, as most letter pairs are shit or just dont even exist!
Also, it would be a great feature to have an Uppercase, Lowercase, Small caps, etc. toggle button added.
Cheers and keep up the great work!~
Will come with the next update, that allows negative values for the "Letter Spacing" input. The text transform options will also be added soon.
* Regarding negative letter spacing, I was referring to the Product Designer in Admin (not the front end as that already allows negative letter spacing)