_ViewImports.cshtml

@inherits R4Mvc.R4MvcBasedRazorPage<TModel>

Index.cshtml

<h2>Index</h2>

<div>
    Test Url DI :@Url.Action(MVCTest.Dummy)
</div>

R4MvcBasedRazorPage

    public abstract class R4MvcBasedRazorPage<TModel> : RazorPage<TModel>
    {
        [RazorInject]
        public MVCHelperBase MVCTest { get; set; }
    }

Startup.cs

   public void ConfigureServices(IServiceCollection services)
        {
          services.AddR4Mvc(/* Hook to add model unbinders */);

        }

T4mvcRegisters

public static class Extensons{
  public static void AddR4mvc(IServiceCollection services){
      services.AddTransient<R4Mvc.MVCHelperBase>();
      // find a way to replace extend RazorPage<TModel>
      // maybe with RazorViewEngineOptions.CompilationCallback
  }
}