Use Angular CLI 6 builder with meteor-client-bundler & TypeScript imports of Atmosphere packages?

I’ve seen a few ways of dealing with Angular client dependencies on Atmosphere packages in Angular-Meteor projects, including:

With the introduction of Angular CLI builders in Angular CLI 6, it occurs to me that it may be possible to forego making Meteor types ambient and still use Angular CLI by merging in a custom Webpack externals configuration.

I’ve attempted this setup by adding the angular-cli-builders as a project dependency, adding them to angular.json, and creating an extra-webpack.config.js but thus far have not been able to create a working configuration. Has anyone successfully attempted this setup?