You sould download the software that is supported by the KeyGen direct from the homepage https://www.silverfast.com/ because there are different languages and OS and each needs a singe download.
I tested Silverfast 8.8.0r14 for Epson
and as you can see the result of the scan test has no watermark
the next test was with LaserSoft Imaging SilverFast HDR Studio 8.8.0r14 Multilingual where I used a low quality source file and the result is also without watermark
the KeyGen was tested on virus total with a great result
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