To give a use case, ./play.it [1] development involves tracking dependencies of binaries (without access to the sources), and translating that to package names for multiple distributions. Being able to rely on pacman-static would allow some of our developers with no access to an Arch Linux system to no longer rely on the availability of some other contributors running Arch during this dependencies tracking process.

[1]: https://www.dotslashplay.it/

You could say the same thing about -Sy when used for a non-root dbpath. It's likewise useful, for precisely the use case employed by checkupdates. Still, we don't support this.

The thing is that dbpath will never be user writable except in edge cases where you have a custom script to rig this up. Just like checkupdates. In such cases, fakeroot is practical.

For the -Fy case I recommend invoking it with sudo, and adding a sudoers rule permitting anyone to use it without a password, given only the exact arguments "-Fy".

Perfectly secure, no prompt for passwords, even unprivileged users can update the files database.

> The thing is that dbpath will never be user writable except in edge cases where you have a custom script to rig this up

I don't think I agree with that. Pacman is a package manager, however it does not necessarily have to manage at the system level.
For example npm and pip can work per user.

I believe the Nintendo hacking group does this. They use pacman to manage and distribute all of their hacking tools using a windows
build of pacman. Where pacman and the packages arre installed just for the user instead of system wide.