You can't modify files, because torrent file itself is just sequence of chechsums. But there is RSS extension that allpo to pipe updates of new files.
I was asking like, how widely is BEP-46 adopted in practice. It's a spec from 2016!
https://www.bittorrent.org/beps/bep_0046.html (discussion on HN at the time, https://news.ycombinator.com/item?id=12282601)