The most important things:
- Make sure your project is razor class library (in your project file the first line should be:
<Project Sdk="Microsoft.NET.Sdk.Razor"> - Make sure your files are in wwwroot/App_Plugins/your_package. This way, they will always be included, because wwwroot is by default included in RCLs
- I personally always set the StaticWebAssetBasePath to just the root:
<StaticWebAssetBasePath>/</StaticWebAssetBasePath>