I imagine Machete's really only calm when he's sleep deprived AF and Vasco would just spend long nights listening to Machete's insane ramblings because he likes seeing him happy.

That's such a cute thought! Unfortunately I'm inclined to believe it's the complete opposite, insomnia makes him progressively more restless and agitated.

You know how after a sleepless night you sometimes get this second wind in the morning? You feel even more productive and motivated than you usually do and aren't tired at all, like a brief illusion of euphoria and invincibility. I think if he skips sleep he might initially get more self-assured, talkative and less inhibited (similar to being a little tipsy). This is probably the point where you might get those insane ramblings. But eventually he'd start going downhill and the cushioning that softens the edges of his anxiety, irratibility and neuroticism when he's in good health and good mood, would wear away and he'd become harder to deal with. He'd make rash desisions and obvious mistakes and get emotional outbursts that he'd regret later. And finally he'd fall into sort of confused, irresponsive and stuporous state where he's still trying to keep going but isn't actually getting anything done anymore, it isn't fun to watch.

He's happiest, calmest and at his best when he's well rested and properly fed. He's able to keep himself running on fumes for a considerable amount of time, mostly by taking several short sneaky naps per day. Rationally he knows this is detrimental to him and that he ends up doing subpar job when he'd tired and cranky, but it's a bad habit that seems impossible to correct.