bizmodeller

I suppose I could ffmpeg all my files (bother), but it would be nice if My Media could normalize the audio across files it's going to play from a playlist.

My Media does honour replaygain settings on tracks (if you enable it in Settings) - so this should provide improved normalization. Not across a specific playlist as such though. Did you see this option? NB it does force all tracks (including mp3s) through ffmpeg as the Alexa devices can't natively support replaygain to our knowledge.