Thanks for your reply.
I tried your suggestion, and I can't tell there's a difference between the clip that's at -19 dB and the one at -21.7 dB.
I also compared -18.8 dB and -21.7 dB, and they sound pretty close to me.
Of course, I'm listening to them over the voices in my head, but still....
One thing I just found, as I'm going through all 22 clips, is that one (so far) had an RMS that was still too low after the first pass of Amplify/Limiter, so it needed another round.
Does that degrade the resulting quality, or is it OK to do two rounds of Amplify/Limiter?
Or is there a better way?
This is all fascinating to me, since I've never really paid this close attention to the technical specs of audio. I've always just listened and, if it sounded good to me, I was done!