It's already implemented in bleeding edge builds of Firefox and Safari, just behind a feature flag (as it also is in chrome) https://caniuse.com/mdn-api_comman

It's already implemented in bleeding edge builds of Firefox and Safari, just behind a feature flag (as it also is in chrome) https://caniuse.com/mdn-api_commandevent https://caniuse.com/mdn-api_commandevent