I have a huge collection of videos I am using for a book. I have over 30TB of data. When I am searching for and downloading new videos for my research, it is a huge benefit for me if I do not download the same videos over and over. So, I use YouTube's download and playlist functions which tells me if a specific video is already on the playlist or any of my playlists, if so, I don't add it and don't subsequently download it. The problem arises when I reach my hard drive's limit. The solution is to download them all to a single hard drive and then I receive a warning if the video has the same name as another already on the hard drive.
So, if I can create a single, 30TB virtual hard drive, out of three 10TB drives, it would make my life simpler.
However, that still leaves a huge problem I have not yet figured out how to solve. These days, unscrupulous YouTubers copy older videos and use a different title, different description, different thumbnail, etc. and then all I have is my memory and the time it takes to watch every single video, sometimes twice, to discern whether it is a copy of a video I already have.