Putting HTML in the footer of a template -> render PDF correctly

Hello!

I'm very happy with this module, thanks to the contributors.

One question: How can I add HTML to the $footer_content variable in a template so that it actually renders it on the PDF? So far it just uses the text function which accepts text only... Or is there another way to put HTML code on the very bottom of the page without using the $footer_content variable?

Greetings
Victor