When tightening the plug it is best done by screwing it in by hand until tight then using a deep socket, tighten it hand tight before using the ratchet to make a 1/2 turn past hand tight. And yes it will still easily turn more, but DON'T... SNUG is your friend.... it is plastic
These plugs are designed to be replaced at least once a year. I always keep several spares with me. I also keep the tools to remove them should they break, including a pipe tap to chase the threads should they need it. You'd be surprised at the number of times I've had to help someone fix their leaking plug, and the look on their face when I tell them they're supposed to replace it regularly.