Poly CTS fitting goof?

[waltsuz]

Anyone here ever forget to install the metal insert on a CTS fitting? I tied into my water line with a Tee and forgot to install them, getting old? The line is covered over/buried....Had no leaks and it tightened up like normal. I realized my mistake after I finished the job....would you leave it? it can't move..
If there's ever a problem I'll dig it back up and re-do it...