Regarding Mudd's "cruelty", it's pretty remarkable that we see two loops where Mudd is convinced he's winning - and in neither of those loops does he choose to crown his achievement by killing Lorca and thus leaving him dead.
Basically, Mudd works his way through a number of steps where he can kill, eat or impregnate people because it doesn't matter. And then we get the "two final" loops in which Mudd actually calls the Klingons. In one, he "callously" kills Tyler. In the other, he kills nobody.
I wonder how Mudd defeated the initial intruder alert at the start of each loop? I mean, first he sneaks in inside the space fish, and then he beams out from there and into a suitably chosen part of the ship, and there he uses his newly acquired experience for shutting down the alarms. But why doesn't the initial transporting trigger the alarms? Just because it is initiated from inside the Discovery?
...Okay, how many loops? Mudd kills Lorca 53 times, but he doesn't kill Lorca on every loop, so that only gives us the minimum (of 56). That amounts to about thirty hours of action already - no wonder he's yawning towards the end! It's not as if he could spend time sleeping between the loops. But he probably realized that and slept well before first stepping out of the fish. Still, there's a limit to how many loops he can do, even on stims. A hundred would amount to staying awake for two days...
Timo Saloniemi