Irans petro-chemical economy relies on Kharg 90% of irans oil exports go from here. So it's pretty significant, and Iran knows this is coming, so they are likely bolstering for the incoming attack. There will be serious consequences for any american that sets foot there.
But Iran has land-links to most of its biggest buyers, the roads are long, but China has paid a lot of money for its belt-and-road initiative for this very reason. Tankers can take the land route.