[4.7-4V]

there `is a guy in the "who has a 100k on their tundra thread" that claims he ran a timing belt 290k. he supplies a photo of the odometer.
says he owns a courier business.

for what it is worth, as we say...

I think you corrected that statement to 190k miles on the original belt.

Driving 190k highway miles in 2 years would be less strain on a belt than 10 years on a belt with 50k miles of short trips and cold starts.
The rubber dries out. The belt gets jerked from a dead stop every cold start with thick, goopy oil on the cam bearings.
Stop and start city driving causes more strain on a timing belt, too.

I have no problem at all believing that a guy with a courier business got 190k out of the original belt.