No, dark energy kicked in much later. And I don't think it's fair to call it a fudge factor. Rather, the evidence shows that the universe's expansion is accelerating; "dark energy" is just our placeholder name for the as-yet-unexplained phenomenon causing that acceleration. A fudge factor is when you massage the data to fit a desired model, like Einstein's cosmological constant, which he proposed in order to cling to his belief in a steady-state universe despite the evidence showing that gravity would cause its collapse. This is the opposite of that -- it's an attempt to explain the evidence, not cancel it out. Just because it's admittedly vague doesn't mean it's dishonest.
On the other hand, an equally unknown phenomenon causing a uniform redshift over vast intergalactic distances would both simplify the model and eliminate the expansion problem. The other question I've been seeking an answer to for many years now is what the data would show if we looked at the redshift ITSELF as an effect, instead of the expanding motion it appears to indicate.