Hi @jespa007, thank you very much for your useful feedback.
We do not recommend or support using both the Pro SDK and Core SDK simultaneously as they have quite different intentions and are produced from distinct business units so interoperability cannot be guaranteed. That being said, I will pass along your feedback to the developers for consideration.
We always try to redirect customers to get the Core SDK Dll via the Nuget Package manager to ensure the latest version updates can be easily applied and used. That being said, you are free to first download via Nuget into the Project directory, and copy the relevant DLL manually should you wish.
Should you wish to add any further information, it would be gratefully received! Best wishes.