I am not a production manager or an engineer so take it with a grain of salt...
SK Rifle Match and SK Standard Plus come out of the same factory and off the same machines. The difference is that the SK RM undergo additional testing and/or inspections to meet their set of quality control criteria. The remainder then becomes SK std+, Wolf or other lower tier ammo predicated by how much time and resources it takes to do the inspections specific to that brand of ammo.
This concept is similar to binning CPUs by their ability to reach high peak frequency and low power consumption. Intel Xeon server processors are well known for this as their highest end processors garner top $, but depending on the batch, some of the much lower cost server processors can achieve similar results... but it is not certified at those frequency and power levels.
Just a random rambling from a chronic tinkerer.
YMMV, happy shooting