Hrm. This is becoming odd.
My mod has 5 template hook location of where it places its output.
With the Postbit Legacy, all locations output only once, with the exception of signature_end.
With the default Horizontal postbit, all locations output only once.
It seems, it's only doubling up on the output when using Postbit Legacy, and signature_end.
Code:
$templater = vB_Template::create($vbulletin->options[cat_postbit_style]);
$templater->register('post', $post);
$template_hook['postbit_signature_end'] .= $templater->render();
Running vB 4.0 PL1