You 2 are both playing the set pretty differently to how it plays in my head.
Flotilla is the parryingest Big Band and I was trying to learn how to parry Peacock's patterns a little better while watching, I struggle to do those plane and bang and bang bang bang parries on reaction. He manages to get quite a few jump ins by parrying planes but I feel he wasted a lot of his ground parries. The parry gives you a gap to really go for something I think, in particular a nice little space where you can do HK giant step.
I also feel Flotilla was being a little too patient, he let you throw bomb patters which I find a little odd, as BB can easily interrupt static Peacock's zoning with kara HP knuckle if she isn't respecting it. Age likes to be highly mobile in this matchup, he rarely throws more than 1 bomb when he knows I have charge and doesn't spend much time on the ground outside my HK A train range. He is very slippery as he knows how easy it is for BB to just ignore his lockdown patterns.
I feel you weren't respecting Big Band's powerful spacings at some points in the game, also the main thing I noticed is you missed a LOT of big punish points and the ones you took, you seemed to squander on short string into Argus. Peacock can do so much to Big Band after landing a decisive hit and I feel you should have been taking those opportunities. You probably know, but Argus is a guaranteed punish on knuckles no matter the spacing, there is nowhere where BB can get this blocked and not be sure to receive the Argus in retaliation. Though Flotilla wasn't really using knuckle much so I guess you didn't need to discourage him.
And this is entirely down to playstyle but I noticed that Flotilla liked to start using his unsafe options once he was in, going for hard reads I think. I like to apply pressure there as I feel that BB has a lot of it then go for the mixup when my opponent is under pressure.