passing ACX

The Limiter should be in the bottom section. If it’s not showing-up go to effects → Add/Remove Effects and make sure it’s enabled.

When I run the Effect - Loudness Normalization function,

Make sure to select the “RMS” option. (Or use [u]RMS Normalize[/u] which is an optional download.)

the RMS is adjusted appropriately but the peaks and/or floors are off.

It’s normal for the peaks to be too high after RMS Normalize. The Limiter “pushes down” the peaks (with very-little effect on the RMS levels).

And since RMS normalize usually boosts the volume, the noise floor will also be boosted. If the noise is out-of spec you’ll need to use some noise reduction, etc. (Be sure to run the low roll-off filter curve first to remove low-frequency noise.)

Recording in a very quiet location,

The requirements are very strict. -60dB is 1/1000th of 0dB. Most of us don’t have access to a professional soundproof studio and the Yeti will generate some noise.