We have a rule though: the account types exposed in
gnome-online-accounts must be used by at least one core application.
It's a good rule because it doesn't make sense to have settings in
control-center for apps that aren't installed by default. So unless we
reverse course and add gnome-documents back to core, the documents
account configuration settings should move from control-center to
gnome-documents itself.
So you're asking that an application with known resource problems re-implements functionality that was offloaded to a GNOME component in the first place. This work, by the way, may or may not be dropped in case we change our minds, and find a use case for Documents to be in the core apps in the future.
At this point it would be much more honest to come forward and say: "GNOME Documents is no more. If you want to work on it, fork it and call it whatever".
Emmanuele.