I don't apply this formula like this: "how SE calculation is made using the 92.35% adjustment, reducing the W2 SS Wage Amount from the Maximum SS Wage Limit of $132,900"

The reduction from the full 15.3% is because the "employer" gets the expense of the employer share. That doesn't change the SS wage limit. It changes the tax amount from the Sched C. They don't owe as much, because it is a self-referential or circular reduction.

I have never seen the reduction applied as a Wage Limit Reduction and that doesn't seem correct to me. Does that work out to the same amount using either the reduction against the max or against the tax?

For the original question, wouldn't the total of all sources of income mean: "The maximum Social Security tax employees and employers will each pay in 2019 is $8,239.80. This is an increase of $279.00 from $7,960.80 in 2018. The Social Security wage base for self-employed individuals in 2019 will also be $132,900."

And that "wage" or Taxable net on the Sched C got reduced by the credit already, as part of the math on the SE.