This is purely just headcanon (and projecting) but I imagine Micah has an extent to how much he can endure before he mentally and emotionally checks out.
In other cases, he’d be an asshole to deal with inconveniences and frustrations. End of chapter 4, into chapter 5 is a bigger deal: the bank robbery, waiting around in that room, scurrying to boarding a ship, the ship sinks and they’re stuck on a raft, they all are stranded on a hot island with (assumed) one of their men dead. I too would be pretty tired! Too tired to pick fights or be a hardass.
Micah is no idiot, he can hold his sour mouth and conserve his energy. I quickly rewatched the Guarma cutscene clips and yeah, he seems to be doing his best impression of a background character through most of it. He still had some snarky things to say but overall he seems pretty pliant and going with the flow of the events. It’s not a whole lot he could be doing when backtalk could result in unfavorable outcomes for all of them.
(Drawing from personal experience here but) It seems Micah lurks. He’s always done that when he isn’t pivotal to a cutscene, but I think it’s fine to look into it beyond “he doesn’t have a speaking role in this scene.” He watches, listens, and doesn’t talk or interact. He does this too in camp, he has bouts of seeming apathetic and dismissive to even talking to Arthur, and not in an antagonistic way, he genuinely just wants be alone. On the first ship, on Guarma, and on their escape ship, Micah does the same; lingering and existing in his own little bubble, observing the surroundings and noticing the bad weather. There is a scene where Micah points out dangerous storm clouds aboard the ship and the way he mumbles is similar to how I sound when not 100% there. I’m corn plating fr…
Micah isn’t all low energy in chapter 5. Trust bloodshed and adrenaline to pump him up and get him back to his well-known self. He also still squabbled with Arthur but they seem more agreeable overall on Guarma, chalk it up to mutual desire to survive.
I also can’t overlook that Dutchie is almost always present. Dutch can turn a blind eye to Micah’s bitchiness, but when it is survival or death and you have less than 5 people to insult, it would immediately be on Dutch’s radar if Micah was rocking the boat.
My final point is: he sleepy. He is tired enough to sleep on screen in a hammock and I think that is pretty damn telling. (I’m exaggerating the importance, but it was significant to me).