I’ve seen this image floating around the internet as an “explanation” for the difference between the forward/backward swirl and the forward/backward brushTrig, but I’ve looked at it a thousand times and still can’t understand what’s going on.

Basically, I’m trying to emulate the play style where you swirl with one hand and accent the snare with the other hand. The problem is that any time I hit the snare, the swirl sound disappears. I can’t seem to figure out why it’s stopping, or how to allow it to continue; as a matter of fact: the image above is the closest I’ve come to a tutorial. Does anyone know how to enable a center hit and a swirl to play at the same time? Is there some MIDI stop function I’m missing?
Superior Drummer 3 version: 3.2.3Operating system: macOS High Sierra (10.13)