Our simple simulation had a 1-second time resolution, so it evaluated the formula for all link positions over the submission's lifetime. But there was no pagination.
We're working on a more accurate simulation that will have many features of real Hacker News, like pagination, new-pages and so on.
I'm thinking again about your question. I think you're talking about the time span a submission is visible on the frontpage, right? This can be controlled by the age exponent in the formula and (in our proposal) by the upvote-threshold between new-page and front-page. If only a few very high quality posts make it to the frontpage (because of an upvote threshold), they will have more exposure.
We're working on a more accurate simulation that will have many features of real Hacker News, like pagination, new-pages and so on.