Hmm, have rarely found youtube comments to be worthwhile, and on average terrible. However use of yt-dl or similar might be the best of both worlds. Newpipe can make that easier.
The Space Time staff read the YouTube comments, pick a few of the best, and then at the end of a later video (usually the next one or the one after that) they present those comments and respond. These comment responses often answer questions that I had when watching the earlier episode.
The videos on the PBS website or in the PBS apps just have the episode.