Can you put "a ton of" somehow in numbers?
As i said earlier, i go mine on need. I go for the surface boulders and start there so my mines are scattered over the map, not in the same chunk as my base, and not that near, often 200-300 blocks away from my base.
My mine is usually not alligned to chunk borders and in the end for sure bigger than 16x16, so it covers more than one chunk.
I recently mined until my inventory was full (first row was equipment, everything else was mined, so stone, iron, lead, coal, nitrate). With auger, without breaks, like... halb an hour (realtime) (definetely not deeper than 35 blocks). Still not a single screamer.
Of course auger increases the heatmap, but how much do you need to mine if you do that in a fresh chunk without reasonable heatmap increases? Here was stated, that while mining the spawn lots of screamers always. Like going 10 minutes in a mine and that will spawn dozens of screamers.
It's NOT. You can mine an whole hour and it will still not increase heatmap enough to spawn a screamer. If you get screamers over and over there might be another source that increases the heatmap, then the mining might give the additional bit to trigger a spawn.