That's the earliest I have heard. I was floored when "Ice" was 'practice crowing' at 2-months. What I have found with both roosters raised here is that the males reach maturity before the females. Interesting dilemma when the get to breeding age.I read with some amusement the discussion of boring Cl hatchlings. My two crested pullets and three little roos are pretty laid back too. The pullets are now 6 weeks old and the roos are 5 weeks old. The roos seem to develop their combs faster than other breeds but I have one who seems to be on high octane hormones. At 3 weeks his comb was pinking up and by 4 weeks he was growing wattles. This was definitely faster than the other two roos. At 4 weeks, the who the first roo games began in earnest. Today, I was shocked, the roo with the now very red comb and wattles (others do not have much for wattles yet) tried to crow! At 5 weeks old, this little guy wants to crow!
I have a EO (basque) roo that started trying to crow at ~7.5 weeks of age and a Swedish flower hen roo who has started trying to crow at ~9 weeks of age.
Sounds like your early maturing roo wants to be 'king of the mountain' and he wants his buddies to know.