Rating: 4 stars

The field works fine. Make sure to put the shortcode in the mail attachments instead of the mail html.
I translated the “clear” button via the Locotranslate plugin. Would be 5 star if they would make that option available.

Rating: 5 stars

Working as expected.
@arael3 Signature image is sent as attachment correctly, if input field name is inserted into attachment section (according to plugin instruction).

Rating: 1 star

– After using ‘Clear’ button, the form is sent, instead of clearing the signature field.
– After form sent, there is no signature in attachments.