Pennsylvania Child Support Calculation Confusion

Wife and I are planning divorce and mediation to define all the details including CS. There are calculators but the results vary and I'm having a hard time understanding the details based on the regs.

I make $146k, spouse makes $73k, with 2 children that we will share 50/50 custody in Pennsylvania.

The CS schedule is explained here:
https://www.pacodeandbulletin.gov/Display/pacode?file=/secure/pacode/data/231/chapter1910/s1910.16-3.html

There is an official calculator tool here:
https://www.humanservices.state.pa.us/csws/csws_controller.aspx?PageId=csws/support_estimator_overview.ascx

The schedule is based on net income, so after taxes we're each monthly about $8692 and $4712, or $13404 total. So per the chart the obligation is $2868 per month.

The higher income is 65% of the total, so
$2868 * .65 = $1864

$2868 * .35 = $1003

When straight using the PA calculator tool, it shows the 1864 and seems one and done. but theres details I don't get. For one, depending the order you enter the incomes NCP vs CP, if I put the lesser as NCP it shows the 1003, which can't mean the lower would have to pay since you entered that way. It can't be conditional on any direction if we're 50/50 so that doesn't make sense.

Theres a 20% reduction on the higher income when doing 50/50 split and this seemingly isn't considered in the tool either. There are checkbox option before calculation, one of them being that the children spend 146+ nights with the NCP. This seems to have no effect.

The 20% is talked about Here
That should take it to $2868 * .45 = $1290.

Specific questions:

1. What is the CS schedule defining? I read that as the total money your combined income is expected to go toward the children.
2. If 1 is accurate, then why would the higher pay $1864 to the lesser household. That would mean one household would have the full 2686 available to them, when they only have the children responsibility 50% of the time while the higher is left with none of it. If both parties split normal home things like food, utilities, travel, etc this should work to give each parent a fair piece of the overall pot, So 1434 in each house per month.