It's based on http(s) instead of bittorrent protocol, so there is no way to make updating torrents without http servers. And it seems, that bittorrent protocol can be extended to support updates without using http links(for instance, using same mechanism as torproject uses for .onion links). Did you consider that option?
It's especially useful for maelstorm browser. Shorter urls looks better, and base58-encoded hashes can be generated using vanity generator to make it more self-describing and readable. Hash type autodetection would be a simple and convinient solution. And there is one more feature becomes available - even shorter hashes by using vanity generator to fill hash with ending zeroes, that can be discarded in base58.