Arrows do imply certain behaviours, if the laws are to be satisfied. For example, they require synchronous streams. This means one can't really do things like coalescing very easily.
On reddit, in reply to the first blog post, someone asked how ZipConduit compared to our parallel streams. Maybe that’s helpful for hosh as well. https://www.reddit.com/r/haskell/comments/10339fe/comment/j2...