should i have hardended exhaust seats installed

I have a set of heads that have already had a valve job done from a race engine that I never fired. I didnmt have hardened exhaust seats installed because at the time they were going to be used with 110 octaned race fuel. Well, now they are going to be used on a pump gas ( 92 octane ) street engine. I have to take them to the machinist today to get the guides milled for viton seals and I need to know if I should have him install the hardended exhaust seats since they will be on a pump gas street engine. His opinion is don't worry about it, go ahead and run the seats the way they are. He said if I wanted it done he would gladly take my money but he didn,t think it is necessary, especially for just a weekend cruiser.