Text:
I consent to Plex to: (i) sell certain personal information (hashed emails, advertising identifiers) to third-parties for advertising and marketing purposes; and (ii) store and/or access certain personal information (advertising identifiers, IP address, content being watched) on my device(s) and share that information with Plex’s advertising partners. This data is used to deliver personalised ads and content, ad and content measurement, audience insights and product development. Your consent applies to all devices on which you have Plex installed. You can withdraw your consent at any time in Account Settings or using this page.
Soure: https://www.plex.tv/vendors/ (Might have to clear cache)
Can also read about the changes here: https://www.plex.tv/about/privacy-legal/
As I said, I've yet to find a selfhosting solution half as good as PlexAmp. It's very, very good and arguably a better service than normal Plex
Thirded on both your points.
The closest thing I've found to Plexamp (on Android) is Symphonium. I only pointed it to my Plex server, but it offers support to so many other services. It also works perfect in Android Audio. It does cost $4, but it's honestly worth that and then some.
But I totally get how great Plexamp is. I use it every day.