Rule, I don't want to break any rules. If the score is bugged I accept it to be removed, but with solid proves.
I had a lot of 1775-1780, some 1785s and 1787s and at some point 1797 came up. All on H2O, no cold. Just by playing with memory timings.
It's no way to cheat at frequency with XTU, so if the app have bugs or issues, it should not be used in competitions. Or the rules should specify exactly what is the acceptable error range, because every benchmark has at least 1% admissible error.