Blazor Community
В последнем обновлении visual studio 2019 16.11.0 добавили возможность Hot Reload:
https://docs.microsoft.com/en-us/visualstudio/releases/2019/release-notes#16.11.0
Docs
Visual Studio 2019 version 16.11 Release Notes
Get the latest features, bug fixes, and support for Visual Studio 2019 v16.11. Download today.