The library currently breaks native custom events used inside the shadow dom on FF67 and Chrome 75 when it polyfills custom events for its own use.
More specifically, in order to have events bubbling up from the shadow dom, one needs to add {bubbles: true, composer: true} as parameters of that custom event. The polyfill viewport-units-buggyfill uses ignores composed and thus the event never bubbles.
It turns out we do not need this library anymore, so our fix was to remove it, but I'm leaving this issue here in case anyone else is having problems with this.
The library currently breaks native custom events used inside the shadow dom on FF67 and Chrome 75 when it polyfills custom events for its own use.
More specifically, in order to have events bubbling up from the shadow dom, one needs to add
{bubbles: true, composer: true}as parameters of that custom event. The polyfill viewport-units-buggyfill uses ignorescomposedand thus the event never bubbles.It turns out we do not need this library anymore, so our fix was to remove it, but I'm leaving this issue here in case anyone else is having problems with this.