Workspaces is ancient in computer years. 
When you are in the Organize Workspaces window, uncheck Show Project Presets so it says Workspace Presets (Global) above the right pane.
Select your presets in the left pane.
Click the > symbol to copy the presets to the right pane.
Now these will be available in all new projects.
Please, no. Anyway Logic does have workspaces, in addition to the single window interface you mentioned.