Errors using Polymer (Vaadin) with CRA

[ccummings]

I'm trying to use Vaadin components (https://github.com/tomivirkki/react-vaadin-components) which use Polymer but am getting this error in production:

Uncaught (in promise) TypeError: Illegal invocation
    at HTMLElement.value (custom-style.js:82)
    at e.value (custom-style-interface.js:85)
    at e.value (custom-style-interface.js:101)
    at $o.n.flushCustomStyles (scoping-shim.js:233)
    at Object.flushCustomStyles (scoping-shim.js:80)
    at custom-style-interface.js:51
    at document-wait.js:42

I've tried adding the webcomponentsjs polyfills but that didn't work. The only issues I've seen related to this in a React context were about various babel configurations in react-scripts@2.x

What am I missing? Is it possible to get Polymer working in CRA without ejecting?

Polymer/polymer#5256
vaadin/base-starter-react#12

[ChristianMurphy]

@ccummings could you share a codesandbox with what you tried?