I didn't like that you can't outright disable transcoding for content served via their app or in the browser. I serve mostly local client and my headless NAS has poor integrated graphics and runs Linux so this was very brittle. Kodi's jellyfin addon can play without transcoding by default so this seemed reasonable.
However in case others want to go this route for a similar use case I hope I can save you some frustration: both this and the native Android app do not handle Dolby vision or passthrough atmos content properly. I also had odd tearing and av sync issues with some large 4k content that don't happen with maven kodi builds.
After a lot of time trying to figure out it, I stripped it out and my shield has no further issues just using kodi despite being the ill famed 2019 tube model. Hdr10, Dolby vision, atmos pass through you name it just works.