I find that the function saveTempContent is not correctly detecting the url paths correctly and hence not inserting the full url into the href.
So in order to get the CSS to load I inserted the link statements in the pdf view, but, again the preg_replace_callback fails to find and matches when the link tag is in the form: <link href="/libraries/koolreport/src/clients/bootstrap/css/bootstrap.min.css" rel="stylesheet" type="text/css" />
It appears the preg_replace_callback will only match when the link tag is in this form: <link rel="stylesheet" type="text/css" href="/libraries/koolreport/src/clients/bootstrap/css/bootstrap.min.css" />
It seems the regex is expecting something between the link tag and the href.
For the moment I have commented out the isAbsolutePath test of substr($href, 0, 1) === "/", and I have ensured that my link tags are in the correct format and it seems to work.
I assume these worked in the past because chromeBinary and nodeBinary work with local executables and they do everything relative to the site root, but these will not work using any offsite pdf renering engine such as PhantomjsCloud.