Thanks for the welcome! After a bit more web research it looks like the tire wear pattern I have is actually indicative of *excessive* toe-in rather than insufficient toe-in. That's a great relief as I would hate to think that the stock specs were not somehow applicable to my vehicle.
I have some homemade tools and a technique which I developed when I had a Nissan Xterra. It gives very repeatable and hopefully very accurate toe-in measurements. That vehicle was happy at +4mm, but the measurement of course is static and so is only relative to what actually happens when the truck is in motion.
Since I'm at the most toed-in end of the specification range on the Suz (+2), at least I know which way to go now. I'll probably try +1.0 mm first.
My sister has '95 Vitara (Escudo) and that thing eats front tires for breakfast!
EDIT: well, I think I'm pretty close at about +0.7mm. It's a very sensitive adjustment - the entire 4mm range is covered in only 1/8 turn of the tie rods!
EDIT AGAIN: A few weeks later, tire wear is minimal and handling is as good as it is going to get, so I'm going to leave it at the 0.7 to 0.8 mm.