Seems to be working, in Chrome at least. Can some other people try it out? http://userscripts.org/scripts/show/112966
Put latex code inside square bracket semicolon pairs: [;...code...;]
For your script, this can be achieved simply by deleting the line in the configuration that sets the inline math delimiters.
I've tested, and the default delimiters seem to work fine on HN.
Testing new version: \(\sum_{i=1}^n c_i \phi(\|\boldsymbol{x}-\boldsymbol{x}_i\|)\)
Not working in Tampermonkey on Android (the script runs, but the notation doesn't happen).
Now using standard MathJax delimeters, \(...code...\) for inline or \[...code...\] for an equation.
Testing: [;\frac{du}{dt};] [;\left[ \begin{array}{cc} 1 & 0 \\ 0 & 1 \end{array} \right];]