I still need to de-Google my Shield. How’s the performance of LineageOS on the Shield? HDR and DV content still playing well?

This is the way! I’m using it too with a piped instance. Also configured the RSS feed to a Slack channel with yattee://watch?v={videoId} which works awesome. When I press the link, when a new video is posted, it opens in Yattee. Basically I have a privacy focused YouTube with no ads and with subscriptions.