I do a lot of business development on behalf of an architecture firm, meaning we have actual PROJECTS and possible PROSPECTS that are in the pipeline (think of applications or architecture competitions).
It would be useful for me to have the possibility to add a new group below projects, containing my “future projects” or prospects.
As a possible workaround, could you highlight all of the projects one colour and the prospects another? When the prospects become projects, you could simply change the highlight colour. That would give you a very quick visual overview of what you’re currently working on.
@Francis_Vanden_Bavie another simple idea is something that I picked up from the community for separating out templates. Set up an empty project that has the title ------------ and you get a nice line you can use as a separator - then you just move the projects above or below. 
