I myself chose Loctite, not for temp reasons....temps mean very little.
That's why in my original post, I wrote...it's the most common...
Most guys use the Red high temp Permatex...
I do recommend the red, or Permatex in general....for anyone that's taking their pipe off frequently, as it's more forgiving...
I've had Permatex leak after a while, more than once...but using the Loctite, never.
My '02 800 Ski doo exhaust...14 yo sled, came assembled stock from the factory with copper silicone as all Ski Doo's have over the years...and in 14 years, has never leaked....and still doesn't, even after being pulled apart for a new short-block last fall, and re-assembled using the 5920.
It's personal preference...it's ok for anyone to use something else, other than what I use...it's a free Country.