So @danbucholtz i’m still reluctant to use the script tag way for those pollyfil, have you found anything about why rollup won’t play nice with them?
The current error in console makes me think web-animations-js issues are with minification, it states:
[14:23:20] rollup: Use of `eval` (in /home/carlos/Carlos/OSGroup/startApp/node_modules/web-animations-js/web-animations.min.js) is strongly discouraged, as it poses security risks and may cause issues with minification. See https://github.com/rollup/rollup/wiki/Troubleshooting#avoiding-eval for more details
The error in web browser states:
The Intl issue doesn’t says nothing in the console, however the broser complains like:

