Thank you for trying to address this problem, as it's important and still bothers me.

But I don't find your idea of two different scales convincing. Consider electric shocks. We start with an imperceptibly low voltage and turn up the dial until the first level at which the victim is able to perceive slight discomfort (let's say one volt). Suppose we survey people and find that a one volt shock is about as unpleasant as a dust speck in the eye, and most people are indifferent between them.

Then we turn the dial up further, and by some level, let's say two hundred volts, the victim is in excruciating pain. We can survey people and find that a two hundred volt shock is equivalent to whatever kind of torture was being used in the original problem.

So one volt is equivalent to a dust speck (and so on the "trivial scale"), but two hundred volts is equivalent to torture (and so on the "nontrivial scale"). But this implies either that triviality exists only in degree (which ruins the entire argument, since enough triviality aggregated equals nontriviality) or that there must be a sharp discontinuity somewhere (eg a 21.32 volt shock is trivial, but a 21.33 volt shock is nontrivial). But the latter is absurd. Therefore there should not be separate trivial and nontrivial utility scales.