Asking a snorer to stop snoring is like asking them to stop breathing. [Asking a snorer to turn over doesn't always help and they are likely to turn over again anyway.] While one may like the idea of asking a snorer to stop breathing, I think one should remember that shelters are like any public place.
You can be as polite or impolite about establishing "house rules", but in the end if you don't like the rules as they develop, it is in your power to leave at any time. Always carry a shelter - sooner or later you will need it.
Live and let snore (breathe).