This is a long shot, but I thought I'd ask anyways.

Data.Vector.Fusion.Stream.Monadic is a quite useful module and I know of at least two packages that could use it without depending on vector, namely massiv and streamly. There are a few others I found, but they are less maintained.
Another benefit of splitting it into its own package would force us to write some tests and maybe even benchmarks for the stream functionality itself.

Thoughts?