I'm liking the Config[Environment](IApplicationBuilder app) method for Startup class convention

https://docs.asp.net/en/latest/fundamentals/middleware.html

And I like the Startup[Environment] class convention mentioned here

https://docs.asp.net/en/latest/fundamentals/environments.html

But I am not sure which one I like more. Some experimentation is called for.

And more research to do on writing my own middleware.