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.
This is what I very much tried. Is the best option out there, but unfortunately the “discover” of new content is really lacking compared to YouTube’s algorithm.