Dear Sugar Support Team,
As of Sugar 10, Sugar PDF doesn't allow customizations, but it would really help if you can allow Custom Class names for extending SugarPDF, just like how the rest of the Extension framework works.
The simple change required is in include/Sugarpdf/SugarpdfFactory.php->buildFromFile method, the class name is hardcoded as:
$class = ucfirst($module).'Sugarpdf'.ucfirst($type);
Can you wrap the class with SugarAutoLoader::customClass - this will enable custom class names which can be extended in the custom/ folder:
$class = SugarAutoLoader::customClass($class);
This will allow SugarPDF to be customized easily using the Extension folder.