@xiota you have just realised that there is more than one way to skin a project cat [1] and so there are several project plugins with differing use-cases. Thats the beauty of plugins, people can make them to fit their use-case or personal preference without fighting others use-cases and preferences. There are several competing approaches to what a "project" is and what an IDE should do about it. Geanys built-in "projects" are extremely simple (essentially named session files) so they don't compete with plugins.
I guess that the place to add your new feature first is whichever plugin you use.
[1] "skin a cat" is a figure of speech, no animals were harmed in the making of project plugins :smile: