I will not be here to compliment you on the excellent product that plex is (I bought the pass on purpose). On the music side, however, you stood still! The plex player is far from the competition as an interface, navigating between albums is cumbersome, the tracks cannot be scrolled, I cannot create a decent listening queue, I do not see the encoding of the original file nor the encoding that uses the dac. … I don’t say to compete with Roon but to try at least … 
You are great 
It won’t help you if you’re only streaming from the browser, but if you have an iPhone, use the Prism Music app instead of Plex’ own app. It connects to Plex libraries and has implemented pretty much everything that’s still on the wishlist for the Plex clients, including CarPlay, proper play queue management, and even search across both Album and Track artists (which the official Plex clients bizarrely can’t do on any platform)
At this point Plex should just hire the developer behind Prism and slap Plex branding on his app.
Plex I use it on Samsung TV and android smartphones (little) in this last case there are various apps that can browse the plex library (usb audio player) … But it is always a matryoshka of software … No? Then I have a mac mini with audirvana and dac teac for Hi Res music! You will understand that a plex app for the world of music would be a twist
Early 2021 clean-up: I take it base on the updates you’ve experienced w/ Plexamp there’s been leaps in functionality/features/usability… → considered implemented
