What´s the best way to add signatures to Documents / PDFs inside Aras?

Hi, we use the Office Connector and also PDF Watermarking for displaying Document States in the resulting PDFs. Certain Document types now must be signed by additional reviewers. To achive this, the first page of the document contains an area for the various signatures. One possible option is the use of digital signatures, which can be done by Adobe PDF readers. But this would require a download/reupload of the file. I wonder if there is also a way to sign documents automatically inside an Aras process? I assume the Watermark option is probably also suitable for adding signatures, but I haven´t tried this yet and I am not sure if this is recommended. Does anyone have experience in handling signatures and can give me some best practice tips? Many thanks! Angela