Though it does fit well i have a couple concerns as far as longevity. The float is plastic and not designed to take a lot of heat. Also being plastic, it may have a different rate of expansion which may cause it to come loose. Lastly the needle though airtight at the moment could free up and leak followed by worst case scenario (however unlikely) of needle falling into the bottom end. Ideally the plug should be the same material as the case to prevent heat expansion issues.
It is a temporary measure