Sounds like it might work, but it doesn’t. I put a console.log inside the onLogin handler but it doesn’t get executed. I suspect it doesn’t fire because the page loads only after the user has logged in. Page not loaded means no onLogin handler, which means no user initialization.
Even if it did work I would have to put in wait logic on each page, because the page onReady doesn’t wait for the site onReady to finish. And if I’m putting in wait logic, I may as well call the user initialization directly. I was trying to simplify the logic in each page’s onReady handler. I could see some use for the site code, just not my scenario.