Finally figured out what was missing. WinForms and WPF deployments need Visual C++ 2015 Redistributable (both x86/x64) to be installed on Windows 10 before calling jsreport.
Not sure about why Windows 7 runs the app without problems and Windows 10 fails but in my case after installing vsredist everything works as expected.
FYI there are 4 versions of Visual C++ 2015 Redistributable (we only need one of those):
Visual C++ 2015 Redistributable
Visual C++ 2015 Redistributable Update 3
Visual C++ Redistributable for Visual Studio 2015
Visual C++ Redistributable for Visual Studio 2015 Update 1
Cheers.