My WP Engine experience is related to a job I’ve been working on for the last week. I wanted to use wkhtmltopdf to generate some PDFs via PHP. Since wkhtmltopdf is an executable file, it would need to allow executable permissions for www-data (or whatever WP Engine’s user name is for apache). I tried to change permissions via FileZilla, but it couldn’t be done.
So I contacted their technical support, and they said that they don’t allow changes to file or directory permissions. Unfortunately, I had to use DOMPDF instead. This only worked because the document I was trying to generate was very simple.