I have a theory on Df's awakening. It goes hand in hand with haki. Rayleigh and the old man from Wano (I know his name but don't want to acknowledge this fucker) said that haki blossom in extreme fights.
So I think it's the same with DF, you have to go near death, through extreme fights, conditions, while using your DF to its best to awaken your DF.
And we know that Luffy actually died against Kaido, Law had awakening after his fight against Doffy where he pushed his stamina at max and also almost died (blood loss, multiple bullets and attacks, arm lost, etc...). It seems like Kidd went close to death against Kaido or maybe against Shanks when he lost his arm.
Lucci stayed unconscious after his fight against Luffy and was close to a coma imo, it's one of the few times where Luffy really wanted to hurt his opponent.
Maybe it happened to Doffy and Katakuri as well.
As for Kaido, seems like he was too strong to be pushed near a state of death to awaken it. And Big Meme was awaken imo.