Firewall behaviour settings question

Have noticed a new checkbox in the “Firewall behaviour settings” dialogue box which was checked by default on install - “This computer is an internet connection sharing gateway (i.e ICS server)”
I have a single PC connected to a router > internet, no ICS - should I untick this box, would there be any benefit - or does it not matter? How does this setting affect the firewalls behaviour?

If your a single pc, I don’t think it will matter one way or the other.