> Feels like it's the only music client around these days that has a functional "shuffle by album" option

foobar2000 has this!

After trying dozens of music clients (including PlexAmp) I eventually settled on simply using foobar2000 pointed to an smb share - nothing else seems capable of properly handling playback by folder structure. (e.g. I've got all my Led Zeppelin albums in the "Led Zeppelin" folder, and I want to just select it and play their discography in album release order.)