I keep wanting to share the featurematrix page with clients pre-loaded with various checkboxes set. The defaults remain the same if no parameters are passed in the URL. Hash-params were chosen to avoid unnecessary refreshes and to avoid impacting search engines.
examples:
featmatrix.html#v=11,95
=> open page, and compare v11 to v9.5
featmatrix.html#huf=1&v=11,95 => compare v11 to v9.5, with hide-unchanged-features set