Gixxer service manual calls for "Thread Lock Cement Super 1360 or equivalent, P/No.: 99000–32130" on brake rotor bolts. Googled it and found a reference to it being for high temp, and also Threebond and Permatex using the number. Couldn't actually confirm your nemeses doing that, but found this:
1360 High Temperature Nutlock (Up to 200ºC) [392 in "press 1 for English"]
Fixing and sealing of bolts, nuts and screws requiring high thermal resistance
The bikes come with a blue patch on the bolts from the factory.
What Loctite would your recommend on my rotor bolts? I'm thinking blue strength but high-temp capability.