Container Snippet placement recommendation now officially changed to <head>
FINALLY! The recommendation for where to put the Google Tag Manager container snippet has changed. The official word is now to put it in <head>
This is significant, because <head> is the correct place for all asynchronously loading libraries, but GTM's documentation had been steadfast in recommending it to be placed in the beginning of <body>. With this change, the library will start loading earlier in the page load sequence, and as a result your tracking accuracy will improve.
H/T +Scott Herman