Hardened valve seats - do they really matter?

I don't know why I didn't think about this earlier in the thread, I actually forgot I had this head til last nite
And the timing of it having become available couldn't have been worse but I bought it anyway since, well, I haven't come up with anything comparable since, either.
The day after I picked up the head I have on my engine as described earlier in the thread from the machine shop, I saw a /6 head come up for sale on CL a couple of hours away.
and the price was too good to pass up. Asking price was much less $$ than I have in the head im currently running.
A freshly machined peanut head, still in the machine shop shrink wrap, done 30+ years ago and put on a shelf.
All new guides seats, valves, everything //for not much more than junkyard core head price. And it still sits waiting for my next motor.
The relevant part to this thread and that head is this: the guy used to run 2 fishing charter boats on lake Michigan each powered by twin /6s.
He sold the boats and retired some years ago, but had gone to the junkyard and got a couple of heads off of "whatever" with a /6, to have as ready spares. Claims the unleaded gas ate up his valve seats. Boat's down, no money coming in.
He had it down to a couple of hours for a head swap, he said he did them so often. So he always had at least 1 done up ready to go.
And he always had "the works" done to them each time he sent one thru the machine shop no matter what they did or didn't need. And dust? Like snowblowers, most outboards I worked on had no air filtering. Out on the water, no dust/dirt cuz the water "held it down". So though I can see a bad air filter playing a part of eating the seats and burning valves but there's gotta be more to it than that. Granted this was a special application that's basically N/A to many of us. But when these boats ran they ran at a steady rpm most of the time.