I have a fully functional, updated Chrome derivative with all the features enabled, and they went out of their way to dynamically load a

  Update your browser to access this website

message as the only visible content rather than test features (which they're clearly doing to GP, so how much work would it be to properly use that feature testing as the main tool for compatability checking) or just letting the browser try to load it -- displaying one of those big-tech "update your browser now" nag messages if they really feel the need to be annoying.