Just took a look at Plotstart - haven't looked at plot boost. I have a chemical engineering background.
It's mainly calcium chloride, with a weight density around 11 lbs/gal and calcium of 10% by weight (stated on the label of a 2.5 gal jug - the remaining 90% of the contents in that jug are water & chlorides which aren't doing really anything for your soil). That means a gallon of plotstart contains 1.1 lbs of calcium & at an app rate of 2 - 5 gal/ac that would put down 2.2 to 5.5 lbs of calcium per acre. This is a very small quantity of calcium.
For reference, limestone contains about 800 pounds of calcium per ton & generally takes over a ton of ag lime to raise soil pH one unit - a ton of ag lime costs less than a 2.5 gal jug of plotstart. Ag lime does take several months to be absorbed which is a marketing pitch for Plotstart (that it is instantly soluble). However, 2.2 - 5.5 lbs of instantly soluble calcium per acre isn't doing much.