Thanks for all the thoughtful tire input everyone!

I work in the automotive aftermarket, so I'm very familiar with all the sizing inconsistencies on tires...same story there. That's one of the reasons I wanted to get specific recommendations here about compounds and widths...there don't seem to be any standards! Thanks again.
I'd like to hear how your tire saga progresses. Guessing I have at least another year of wear on my SL's 38 mm Pathfinders, but someday I'll have to replace them.
Not gonna replace wheels just to fit a tire, and not quite ready to ditch my 5.0 EQ fenders. So I
think that limits my biggest tire to the 700 x 38 mm on the bike now.
On a tangent
Isn't it odd how humans across the planet seem to be drawn to big tires? Not just a US thing. Look at the evidence:
o Toy vehicles (cars, trucks, motorcycles) always have huge tires these days.
o Vehicles in prominent roles in cartoons, ads, TV shows, and movies often sport big tires — apparently for the same reason that their producers gravitate to D cups.
o Aftermarket mods often involve bigger tires (my old roaster included) — often at great cost.
o All hot new vehicles for sale now come with big tires — often with options for even bigger.
o Fatties are by far the most popular ebikes out and about in coastal SoCal — despite all the performance disadvantages for most riders.
o Fatties also dominate the ebike reviews and ads I see online.
o Now that performance data brings legitimacy to bigger tires on road bikes, every GCN road or gravel bike review states maximum tire width, with wider clearly being a selling point now.
And if that's not compelling enough, I recently saw Simon of GCN complaining that a bike he'd been assigned had only 47 mm tires. If a guy that performance-driven has already gone over to the wide side, you know it's like crack.