Focus stacking is a technique designed to increase depth-of-field by taking
multiple shots of the same scene with the lens set to a series of focal distances.
But focus stacking cannot possibly correct any lens aberration that causes
the image plane to be unsharp regardless of focus: Spherical Aberration, Coma,
Astigmatism, Petzval Field Curvature, or Chromatic Aberration.
That's because the same aberration is present in each image taken by that lens.
A detail that isn't resolved in any of the images is lost forever. Makes sense,
doesn't it? Software isn't magic.
(Backfocus stacking could theoretically be used to correct Petzval Field Curvature
on a camera that has an adjustable back focus. Never heard of being done, though.)
In any case, focus stacking requires a very steady tripod and very accurate focusing.
And nothing in the image (e.g, leaves in the breeze) can move while all this fussing is
going on.
Other software programs can sometimes correct for some types of Geometric
Distortion, because it doesn't make the image unsharp, merely distorted.
If you plan to enlarge your images to the point where people can actually see
detail, there is no substitute for having a high-resolving-power lens.
Alas, Hamburger Helper will not make ground rat taste like top sirloin.