It already has the Activities button so it makes a perfect candidate for a fork.
GNOME Files (also known as Nautilus) needs to have an ability to add Linux VFS directories as Libraries which would be then be stored in a virtual tag-based file system on a higher level of abstraction. Then libraries can be properly tagged by the user or GNOME itself in case of mechanical tags which can be inferred from the file itself (think [MediaInfo](https://en.wikipedia.org/wiki/MediaInfo)).
Once tagged libraries are implemented, it's all about adding a proper UI to create and manage activities.
One can envision the development in phases. And it makes to brainstorm for both ends.
### Final phase
In this phase the system knows the user even better than the user themselves. It automatically figures out the needed activity and sets all the files in advance so the user is left with the absolute minium amount of work. 99% of stuff is automated.
Some automatic tags are too expensive to compute every time the file is changed. Hence, it makes sense to store a flag on file modification that tag value has to be freshly computed next time it is queried. Then there can be a command similar to [`sync`](https://linux.die.net/man/8/sync) to force recomputation of all lazy tags.
