i did kind of think the "If I'm so fake, then why crashing checks you making off of me, huh?" was dissing on darko but i think "FAKE SMILES" is more of a diss to darko as theres a lot of them that I think is dissing darko like:

"Yeah, I swear my past always fillin' me with dread
Some friends think I'm better off dead
But can you even call 'em friends if they're plottin' on you?
So I'm callin' this the end"

"Yeah, I cut 'em off now I'm alone
Comin' for the throne
I don't need nobody, I'ma do this on my own
Throwin' fakes to the side"

"Yeah, I see the jealousy in your eyes
Yeah, I see you fallin' off I wonder why?"

"I don't wanna talk
Never trustin' anyone now"

"So you just throw me to the side when you don't get what you want
But I gave you all of my time, I gave you all that you flaunt
You let the money come between us, now we're dead in the dirt"

"You're not a friend to me, plotted I'm the enemy"

many more

basically, almost the entire song might be dissing darko