Steve has one, too.
https://forum.audacityteam.org/t/noise-gate/14017/1
Both the noise gates and the newer Noise Reduction try to recognize valuable content and route the correction around it. This allows much better reduction between the words, but worse reduction during them.
A common complaint with the older one was it was impossible to adjust it down far enough. The slightest nudge of the correction control and you had too much. You got the impression that if you could fully adjust the bottom 10% of the slider, that would do it. That’s probably why the poster had to resort to dual-channel tricks to get it to work. I never got it to do anything valuable.
I got rid of most of your hash and noise by just eliminating the DC signal.
Koz