In addition to the workspaces that I own, I get shared to individual sheets (listed under 'sheets' instead of workspaces) and partial sheets within other workspaces I do not have full admin rights.
This poses the inability to move shared sheets to my workspace and reorganize sheets or partial workspaces owned by others into my own workspace without posing the risk of changing ownership to some of the sheets.
I suggest having the ability to create groups or collections of shared sheets and partially shared workspaces with limited access rights, with my own workspaces and sheets on related projects. This would be similar to creating a 'collections' feature on BOX.