Looks great!
I started a similar project some time ago (offline build time license validation). I think your project will have more traction, so if there is anything you like in NuSeal, let me know and I'll try to port the features to SponsorCheck.
github.com/fiseni/NuSeal
github.com
GitHub - fiseni/NuSeal: A .NET library that helps you protect your NuGet packages with commercial licenses.
A .NET library that helps you protect your NuGet packages with commercial licenses. - fiseni/NuSeal