Thanks!

There's multiple ways of achieving what I am mentioning. In reality though there are only a "few" types we are registering so you could even register them in code with a TypeCatalog.

Alternative is we could just go to use MEF on nuget (which I'd like to do) and then get rid of attributes and use RegistrationBuilder which we can supply lambdas to properly filter.

If you wanna do that, I'd be up for taking it in.