You won't contribute to projects (excepting GNU) with *any* copyright assignment? So, of the menu of options described in Jon Corbet's article here, you won't agree to any in which the first choice is "The contributor transfers ownership of the contribution to the project and gets, in return, a broad license for further use of it." but will agree to some of them in which the first choice is "The contributor grants a broad license to the project, but retains ownership of the contribution."?
Or did you mean something else?
For the third time, I'd like to emphasize that I'm very glad the Project Harmony folks have done this work so that we can have this conversation. It would be a shame if my licensing policies were turning off potential contributors unnecessarily.
P.S. When I create a project for facilitating collaboration among Software Freedom-loving pirates I'm going to name it "Project Arrrrmony".