If the spores really are only an inoculum, that should keep your kale area supplied with spores. And any weed seedlings would pick them up and multiply them.
(What I've said in this thread is just my belief, not things I've seen directly supported in print.)
I think some mixing and re-aerating soil is a good thing, but I have only worked with heavy clay soils and most of my beds are still pretty heavy and tend to "settle".
