The alternative player still shows 1080p for me. Here's the links to download it:
Chrome:
Firefox:
Chrome:
Alternate Player for Twitch.tv
Alternate player of live broadcasts for Twitch.tv website.
chrome.google.com
Alternate Player for Twitch.tv – Get this Extension for 🦊 Firefox (en-GB)
Download Alternate Player for Twitch.tv for Firefox. Alternate player of live broadcasts for Twitch.tv website.
addons.mozilla.org