There are several comments regarding that if one cannot pay for an opposing forensic investigation, then forensics is a black box.

Either you are moving the goal post, or I am to donnish.

Let's agree that it is scientifically not a black box, but some may not be able to pay for such service.

There were suggestions of nationalizing, centralizing or governing forensics and just have one, unbiased working for the courts.

This diametrically opposed to the problem pointed out by many where prosecutors will use specific labs because they return more positives. If the prosecution and the forensicator work for the same employers, how is that prevent further erosion of this problem?