Go to the 3rd gen forums. Tons of stories of rubbing boots failing in thousands of miles or sometimes even less even with OEM.
"Not everything you read on the Internet is true." -- Abraham Lincoln
I only know I've personally owned two IFS Toyotas over the span now of 23 years and put roughly 300k miles on the combination of the two.
According to my logs I replaced 4 boots on the old truck, one pair when the originals split and I built two spares from junkyard salvage (not sure if those went with the truck or not). I don't know if Martin or K.C. have had to do axles or boots. But if it's got the set I put on then the originals went 17 years (it was a Japanese-made truck, so there's that) and the pair of OEM replacements I did in 2008 would be about 15 now. They weren't abused really but were Rubicon-proved anyway. I did eventually take some lift out but for most of its life the 1991 ran 1.5" BJ spacers and 25mm bars, so it was at the maximum lift it could take.
On the current truck it's just the two originals that split so I'm at less than a year, about 5k, into the experiment on one side and 3 months and less than 1k on the other. I don't run a ton of lift on this truck because, like you say there's no reason to tempt fate. I'll just have to see. I did end up finding two extra axles for my 2008 so I've done 4 boots on it, too, with the spares I have set aside.