I had an Applied mixing class at college recently. It’s basically a weekly private lesson. I was bringing in some drum recordings I did at the house. During our lesson he mentioned putting an additional (very close, almost touching the drum head) mic on each drum to track with. Those tracks will be muted but will be used to trigger a noise gate or compressor. Is there any benefit for this? Also wouldn’t it be more efficient to use a trigger and record midi data to trigger the compression or gate rather that using an audio track? Edited for clarity.