Hybrid angular app throwing error "'./app.module.ajs.js' does not provide an export named 'default'"

Question

I am attempting to convert my AngularJS project to run as a hybrid (i.e. 1.x alongside 2+) following the bootstrapping steps provided at the angular.io guide page provided specifically for the task. I have followed the guide with some modifications (primarily just so that I could maintain my existing project structure). My steps in inexact order have been to

• include webpack
• convert my original app.module.js and all angular modules declared therein to exportable ES modules
  • (app.module.js became app.module.ajs.ts, which is transpiled to .js)
• add a new app.module.ts for manual bootstrapping, as per the docs (looks identical to the file of the same name in the docs) and remove the ng-app directive from the html as it is no longer necessary
• import the modules into all dependent controller, direcive and service files.

Now when I serve the project, which I believe is the step I should be on (the steps seemed pretty straightforward...) I get a slew of the same error:

However when I open that file up, I do actually see exports.default = ariaApp. Also, the .ts file by the same name does indeed contain the declaration and the default export

const ariaApp = angular.module("ariaApp", []) 
export default ariaApp;

Has anyone seen this before? / Does anyone know what this error indicates? It seems totally off... All suggestions appreciated! Thank you!!