Aurelia-web-components plugin testing

I am attempting to test: https://github.com/aurelia/web-components using:

Operating System: Windows 10
Node Version: v8.10.0
NPM Version: 5.8.0
Browser: Version 66.0.3359.117 (Official Build) (64-bit)
Browser: Version 68.0.3399.0 (Official Build) canary (64-bit)

Code is here:
https://github.com/constructor/aurelia-plugin-tests/tree/testing/aurelia-web-components

I am getting error:
Unhandled rejection TypeError: Cannot read property ‘isInitialized’ of undefined.

Note from https://github.com/aurelia/web-components: This plugin requires that your browser have native support for the CustomElements v1 spec or that you have configured a v1 spec-compliant polyfill prior to calling registry methods.

Custom Elements v1 is 100% in Chrome versions > 67.

I get the same error in both listed browsers. Anyone point me in the right direction?