Low Rolloff is step one in the Audiobook Mastering 4 Suite.
https://forum.audacityteam.org/t/audiobook-mastering-version-4/45908/1
The suite is designed so the tools clean up after each other and taking them out of order or leaving any out is not recommended. Depending on your recording/announcing/presenting style, you may want to add steps, but at either end, not in the middle.
Because mastering 4 doesn’t feature an Effect > Compressor step, it doesn’t have pumping noise and you can do other effects, filters and corrections either before or after your read. Two popular ones are Noise Reduction and DeEsser.
DeEsser doesn’t come with stock Audacity.
https://forum.audacityteam.org/t/updated-de-clicker-and-new-de-esser-for-speech/34283/1
It’s strongly recommended you make WAV (Microsoft) 16-bit copies of each raw performance, so If Anything Happens during editing, you never have to read the work again. It is noted ACX puts great stock in having your chapters match, so you probably can’t tune each chapter (other than patching pops, clicks and wet mouth noises) and you can’t change your production technique in the middle.
On Wednesday last, BrittanyS was accepted for ACX publication.
Koz