Very cool extension! A lot of work for sure
So if I understand correctly you add to the existing footer tpl using settings from the settings table?
I would definitly create my own controller and matching tpl and as for the choice of keeping the original, you can just add it as this->load>controller as of version 2+ and getChild() in OC1+
So create your own controller say customFooter extends Controller...etc
and add $data['original_footer'] = $this->load->controller('common/footer'); which can be echoed in your own custom_footer.tpl if your customers choose to. So
echo $original_footer would display the footer as we know it but from your own controller.
The only ocmod would be to hide the original footer: replace: <?php echo $footer; ?> with <?php echo $custom_footer; ?>
In OC2+ you cannot use any version of $this. But for OC1+ I would do the same. Now you have all vars from your own controller to pass easily.
Hope it helps, let me know if you need more info.
Cheers
Attn: I no longer provide OpenCart extensions, nor future support - this includes forum posts.
Reason: OpenCart version 3+
Thanks!