While many savvy users can turn a infohash into a magnet link it's nice to be able to message someone a hash and have them add it without having to turn it into a magnet link manually since some message programs either block magnet links or turn some characters into emoticons. I would be interested in doing the work to add this assuming the KDE team is okay with the change.
If you have a patch, please add it to https://phabricator.kde.org/differential/diff/create/ and put the link here.
A possibly relevant merge request was started @ https://invent.kde.org/network/ktorrent/-/merge_requests/15