I have given up on using the "far far away" title generator and have gone to the "basic" title (which itself has some issues - namely firuring out how to get all the text on the screen.)
This type of title/text renders in a reasonable timeframe, so I have concluded that it was the amount of scrolling text and the length of the title (1 minute 10 seconds) that was causing the s-l-o-o-o-w rendering times.
I did a small test with just the default parameters for "far far away". It rendered in an ok time. I then lengthened the time to the 1 minute 10 seconds and the rendering time became much longer. I did not go any further with adding real text so changing the font/size/color.