I have alittle over 1,800 miles on mine. I checked it n blew out all the dust in belt housing and let me tell you it was very very dusty in there lol but i did check the belt at 1,650 miles and all is good so far and put it back on. I do carry a spare belt just incase but my original belt still looks good. I also have a 2018 polaris RS1 n have over 5,000 miles on the original belt, and its belt still looks good as well. Every 1000 miles I will clean and blow out belt housing and pulleys like I do to my RS1.
We rented a second KRX on our trip to Moab. My daughter was driving the rental and every time she started from a dead stop, the tires chirped. We took it back to the shop and they pulled the belt. When I looked at it, the belt looked almost new. The installer said once they stretch a little bit, they have to be changed. Not much of a tolerance on them.
Belts dont stretch they wear but not enough to see with the naked eye. Visual inspections are somewhat pointless since they can look prestine up until the second they decide to let go. Its not like checking a set of worn out tires.
I hit full bars on Belt temp and it was flashing at the end of a 300 km in 2 days of riding.... any ideas, machine only has about 600 km on it, and first service was done. I plan on removing the clutch cover today to further inspect.