Indeed, the same issue. There is currently no way to specify that in the plugin configuration, and the next update will remove your customization.
I’m happy to add the functionality, though, as long as we can set it up to be generic (i.e., add a dropdown list in the admin area to include selected custom fields). Right now, that part of the admin area is a bit untidy, with large rows for such options and only standard things for the header.
Resize featured image:
There is a test fix for the featured image alignment/sizing issue in the trunk (see here), however, it is not without issues (yet).
To manually adjust the code for your preferred styling (which would then apply to all featured images), see lines 370-388 of wp-post-to-pdf-enhanced.php .
Adding custom css is another issue currently under development. As this is an all-volunteer thing for me, I can’t make any promises as to when such things will be fully implemented, but I’ll try to add & fix things in the order requested (and the order of difficulty!). ??
Cheers