What is "Set Output Path" ?

This  simple addon will automatically set all your scenes output path depending of your filename and your scene name, and render your image or video outputs in a subfolder where your file is saved.

Where does the versioning come from ? 

If you have purchased and use my "Snapshot files addon" (https://blendermarket.com/products/snapshot-files), the output path will also use the current versioning of the file !

Why is it useful ?

It's a time saver, because your don't have to set up by hand all inputs. And time is important !

Is it finished ?

For now, you can't change the output pattern, but my goal for the 1.0.0 version will be to let you configure the button behavior.