@chrisgraham I fully agree, and have been considering making a pull request to do this, or least investigating how difficult it would be. Being able to change into a source directory and type `geany .` and not have fiddle with making/closing/opening projects would be super handy. SublimeText and VSCode, two other editors I use from time to time, also do this.
@elextr using plugins which add even more ceremony to opening/using projects is the antithesis of this feature request.