I am happy to release an alpha for a .NET Core SDK that you can use to build ASP NET Core and Azure Functions webhook based SmartApps using the new programming model. Currently supporting .NET Core 2.2 and 3.0.
The src and details can be found in the GitHub repo.
Nuget:
2.2.14-beta for .NET Core 2.2
3.0.7-beta for .NET Core 3.0
Eager to get feedback and happy to take on contributors!
Many Thanks,
Ian Bennett