One of the most useful ways I've found to learn about a deeply niche topic
One of the most useful ways I’ve found to learn about some deeply niche topic is to find a recording of a tutorial or workshop aimed at a research audience, and watch the video about 5 times slower than originally intended.
It usually makes more sense than attempting to read the papers the video is based on (and is self contained with all of the key important information), but the significant speed decrease is necessary because these research talks are freakishly information dense, and also, unlike the intended audience, I have no idea what the speaker is talking about.