Peak CoO ability is FS
Katakuri was able to sense BM and Luffy moving in seducing forest while he and pero was at sunny
His CoO isn't only great in prediction.
Kaido and Luffy didn't detect Mr.Go
Are there worse than Garp or others in CoO?
The reason he didn't detect Flampe is the same why Kaido and Luffy couldn't: they were too focused on each other
Oh BTW Flampe was far hiding
Caesar was also hiding ail bit away. He wasn't close to Katakuri or else he'd be detected
Shiryu got close to Garp While attacking, got detected and low diffed
let Shiryu fight Katakuri 1v1
Or 2v1...He shouldn't even dream of getting near
He should spam sneak attacks from afar or else he gets brutalised
In fact, if Katakuri knows your presence
1v1 or 1v3 or 2v4...he's not losing
Goodluck to Shiryu landing a move 1v1
FS is the peak of pre-cog, which is one aspect of observation. It has other advanced aspects like...
presence sensing that Fujitora uses,
being able to see through things like Usopp,
hearing like Kaido and Enel,
emotion sensing like Luffy, etc.
Flampe was on the battlefield all along while Kuri was bullying Luffy while Mr. Go came out of nowhere in the middle of a clash. He didn't fail to notice her in the middle of an intense clash—he failed to detect her while giving Luffy a one-sided beat down. Kuri has shit-tier detecting skills while his pre-cog is top-class. Don't confuse the two. Pre-cog is as good as useless against invisibility.