I wound up using StatCache. I forked it and made a PR that adds an option to minify the HTML when written to the filesystem.
https://github.com/opengeek/statcache/pull/27
And I got my perfect page speed score!!!
$this->modx->resource->_output = preg_replace(
array(
'/ {2,}/',
'/<!--.*?-->|\t|(?:\r?\n[ \t]*)+/s'
),
array(
' ',
''
),
$this->modx->resource->_output
);