Close Other Projects
Now that we can open multiple projects, it would be nice to be able to close all other projects. Currently you can either close the current one, or all projects.
Could work similarly to the Close other Timeline Panels function.
This has been implemented for some time (14.x); sorry for the late update!
If you select "Close Project" in the file menu, only the project currently selected will close. In other words, the Project window of the project you want to close.
I am working on multiple projects. This would be handy and easy to implement I guess :)