One thing to point out is lights that extend past the muzzle tend to collect more GSR than ones that end behind the muzzle. They’ll both get some on it and you’ll need to clean the lens periodically.
The advantage of having the light go out past the muzzle is that if you press the gun into someone it won't go out of battery. Like for instance in a struggle and you are pushing the gun into the attacker it can still fire.