Gas bottle adapters

If you already have the gas fuse, but it is POL to POL, I wouldn't bother.

I have never found the need to ensure anything other than tight fittings.
If the fittings are in good condition they will provide a sound seal.
Just check the rubber sealing rings from time to time for any nicks.

If you are in any doubt as to possible leaks, use a bit of warm soapy water, trickle over the connections and check for any bubbles indicating a leak.

A routine soapy water test would be a better safeguard than a gas fuse

HI
As others have said
A gas fuse like any fuse will only trip when the flow rate exceeds what it is designed for
That means a busted hose/ pipe or similar leading to a heavy gas flow

They can detect that a minor leak is in the system , if the gas is turned off at the bottle, & sometime later the gas fuse needs to be reset[based on pressure loss in the system ]

PeterQ

The Gas Fuse is useful too as an indicator of gas level, but there are other ways of revealing this.