how about a plug-in to handle the noise floor limit on the ACX check plug-in? we have very good “peak plug-ins” and one for RMS control. With the noise floor limiter it will help a lot of us to bring our product into compliance with all three of the ACX check plug-in parameters, especially those of us who are not dyed-in-the-wool broadcast engineers, and for whom a lot of this technical geek-speak might as well be Sanskrit. 
Noise is harder than it looks.
There are several different varieties of noise and we designed techniques to deal with each one individually (except one or two deadly ones).
https://forum.audacityteam.org/t/audiobook-mastering-version-4/45908/2
You might well say apply them all and be done with it except for a submission requirement not to overprocess. Anyone can beat their voice with a stick repeatedly until it satisfies all the ACX requirements. Several readers tried that. It usually makes it past the ACX robot which is only looking for the three sound values, but it will not make it past Human Quality Control. The human is not going to pass a voice that sounds like a bad cellphone, and by the way, noise processing is one of the reasons cellphones sound like that.
ACX’s goal is somebody reading to you in real life, or as I put it, somebody telling you a story over cups of tea.
So it pays well to figure out which noise you have (in English from that page) and apply the appropriate remedies. If you’re not sure what you’re doing wrong, post a test. Post if you have trouble applying the corrections.
http://www.kozco.com/tech/audacity/TestClip/Record_A_Clip.html
Koz
I did design a Professional Audio Filter which when applied to your field sound shoot would remove most of the major production problems and then a follow-up process which worked mostly on voices. The voice one was interesting. It could pull a clear voice recording out of busy street noises or rescue a restaurant interview.
I published them both on April first.
Koz
Please note the date code at the top of this posting.
http://www.lafcpug.org/phorum/read.php?1,250984,250984
Koz