The individual torrents are only a couple GB to a couple TB each. You can automatically generate a list of torrents of how ever many terabytes you are willing to seed
It seems you can specify the storage space you want to devote, and it will suggest torrents to match. For example, duxiu is only ~40gb. This is separate from torrent-client limiting -- you can just seed specific parts of the collection if you want.
You don't have to download all files in the torrent. Most torrent clients support partial downloads and you would only seed those parts. The main concern would be that you would be undoubtedly distributing copyrighted material
Most torrent clients let you select subsets of file to download (and thus seed) so you can choose a portion to download whatever amount of disk space you are willing to lend.
I would if I could though, so excited to see anyone answer the call!