Just a thought. If the DNA were run through 2 such holes, you could use a nearby non-uniform sequence to clock the reading of the other one. Not a magic bullet, but maybe an improvement. Assumes the readers can be close enough to bound the amount of slack between them, and that they dont interfere with each other.
A single flow cell contains a few thousand pores (I think this is what you mean by "holes") that are all at different stages of passing different molecules, with signal data being captured from a few hundred at any given time. In practice you'd never expect (nor could you arrange) for two pores to be at the same stage of processing the same (or any pre-determined) molecule at the same time, so correlation information like that is out. The "clock rate" is determined by the so-called motor protein that "pulls" the nucleic acid molecule through the pore, if you fancy going down the reading rabbit-hole...
No, I meant a single pore with two readers. So the same molecule is being read at 2 positions. Movement might be detectable in one, but not the other because it's full of repeats.