Very fun episode. The animation was decidedly meh with some widely inconsistent art throughout. The manga chapter was pretty hectic in parts and the anime tries to flesh out those scenes with mixed success.
As far as filler, everything with Brownbeard was gold. The extra scene of the dragon biting Brownbeard's tail to give him a speed boost with everyone cheering Brownbeard with him responding "You people are horrible!" was a personal highlight.
I don't feel the same way about the Franky farting filler, but seeing Franky fly away on his farts like an ass-powered jetpack is bizarrely satisfying. Strangely, Franky's fart clouds are one of the best animated things in this episode.
It's funny, they never did explain how Franky split up from the group in the manga, so apparently he just farted over all the poisonous gas? Was this Oda's initial idea or just a lazy plot hole?
There were a lot of things not shown in the manga in this chapter that was merely alluded to. Very hectic. We do learn in the manga that Franky can still use his Coup de Burst/Boo techniques, so I guess were were suppose to connect the dots there. Same with the dragon biting Brownbeards tail giving him a speed boost and where/how Brownbeard got a battering ram right before reaching the door. There's probably more.
That's just seriously contrived writing. All i can picture is Law asking them "hey, can you good people use THAT chain on me, please?". That is, assuming he wasn't passed out anymore. Urgh.
Not really disagreeing about the contrivance there, but I'm guessing that he ended up with those cuffs by chance and they could have ended up on the Strawhats, Smoker, or Thashigi. As you say, there's no way he could somehow guarantee to have those particular cuffs put on his wrists while captured. Unless he purposely got captured and managed a switcheroo when no one was looking or …. something. Certainly could have used more elaboration there.