With the latest release of the Qlik Sense .NET SDK (version 13.19.0) we have moved the support for .NET Core out of its experimental state and it is now considered fully supported. The officially supported .NET platforms are .NET Framework 4.5.2 and later and .NET Core 2.1 and later. The release is available for download through nuget:
https://www.nuget.org/packages/QlikSense.NetSDK/13.19.0