First, I'll admit that I am in some different reality from most on this site because, I get different results from most here as follows ..
1) My TXC250 -- ~950 hrs before it needed a rod kit and different piston and rings (different engine from yours but still a Husky)
2) My 2010 TC250 from WY - 140 hrs and kicks a$$ today
3) My 2010 TC250 from WA - 220 hrs -- gets rid of some oil but kicks a$$ also. I have new rings (only) that I will replace shortly.
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1) I do not change my oil after ever ride.
2) I do not clean my air filter after every ride.
3) I do not burn super-duper gasoline in my bikes.
4) I do not have have PRO mechanics work on my bikes in most cases.
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I try to stay off the REV limiter as much as possible on all my bikes; After ~10K RPMS, the bikes don't really make any more power so I change gears

.. Staying < 6K on the RPM scale, as you have stated, is well under the limits of these engines ...
My bikes are not raced on tracks alot but I do race some as what is shown in the race reports section. I'm mostly a trail rider with these TC, racer models. I've got > 300 ride videos on youtube on my 250TXC channel ... Lots of ride reports here in the Cafe ride reports but not sure how many on just the TC x-Lite engines ...
I'm doing some ride testing now (as a way to pass the time) between my 2008 WR250 2st Husky and these new fangled 250cc 4st Husky bikes so expect about ~30 more timed, ride reports from me and my Huskies in the near future ... Nothing abusive, just plain ol' dirt bike riding from an amateur, country boy rider who uses a helmet cam for timing specific trails.
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There is a PRO Husky mechanic \ employed guy out here on this site and he recommends to run 0w-
40 WT oil because the 40WT oil will flow better in the engine than the 50-60WT stuff and it stopped them from toasting engines when they are racing Huskies on their professional level ... I can't see a reason not to ride with these guys (Zipty Racing and Tinken) .. So I'm running 5w-
40WT oil as much as possible now. And again, I'm not abusive to my bikes. Just plain, Husqvarna, dirt bike riding ...
Your riding results may vary from mine and others ... I've only really owned Huskies in my life and maybe that is why the Husky gods smile on me so much.