Make MSBuild 2020 player stretch across the window and chat below. Hit F12 and paste into console.

msbuild.js

// F12 Dev Tools and copy and paste into console!
// Stretches studio player 100% and chat below.

var studioPlayer = document.querySelector("studio-player");
var studioVideo = document.querySelector(
  ".home-page__live-stream--content__video"
);
var chat = document.querySelector(".home-page__live-stream__info");
if (studioPlayer && studioVideo && chat) {
  studioPlayer.style.display = "block";
  studioVideo.style.width = "100%";
  chat.style.height = "600px";
  chat.style.width = "100%";
}
var content = document.querySelector(".session-detail__content--grid");
var sidebar = document.querySelector(".session-detail__content--side-bar");
if (content && sidebar) {
  sidebar.style.float = "none";
  content.style.width = "100%";
  content.style.float = "none";
}
var viewContainer = document.querySelector(".view-container");
viewContainer.style.maxWidth = "100%";
viewContainer.style.padding = "0";

Sessions:

var content=document.querySelector('.session-detail__content--grid');content.style.width='100%';content.style.float = 'none';
var sidebar=document.querySelector('.session-detail__content--side-bar');sidebar.style.float='none';

@zo0o0ot Updated and posted for session page. There are still margins. Fixed, script works on both homepage and sessions now.