All of those are really fun and I want to see art and stories featuring every one of them. What'd be really cool as well would be pieces featuring multiple null characters who each have a different orgasm response, so that you can have multiple of those ideas mashed together to see what kinds of shenanigans would come about then.
Here's another idea as well though:
>null characters don't ever orgasm
>instead, once a null character's pleasure has climbed high enough for them to hit what would normally be the pre-orgasmic plateau, they find themselves stuck
>at the point where a character with genitals would find their body just naturally pushing them up off the plateau and into a full-blown orgasm, a null character finds themselves just straining harder and harder against their plateau with every further bit of pleasure they receive
>finally, with enough arousal, with enough stimulation, or with enough sheer mental effort they finally manage to push past it
>but that doesn't mean they've hit their climax
>instead, once they've managed to push past the plateau, they find their pleasure just climbing higher and higher once more, making them experience every sexual sensation more and more sharply again as they come closer and closer to their next plateau
>their next plateau is that much more of an intense (and potentially intensely frustrating) experience, and requires that much more arousal, stimulation or sheer mental effort for them to push themselves through, but then...
>with every plateau they manage to push themselves past, it becomes clearer and clearer to see that the only limit there is to their pleasure is just how much of it they can take...!
>finally, when they find themselves too overwhelmed or too exhausted to continue, that's when they can then find themselves floating back down through every level of their pleasure until they finally find themselves just drifting into a pleasant, quite certainly well-earned afterglow
I think that's something that's lewd and also cozy to imagine~