Problem: Now I have to log in seperately at all projects (like the Wikpedias, Wikibooks, Wikidata), even if I am logged in to Commons, though the inlog codes are the same for all projects. Sometimes I forget it and then my edits are registered on my IP adress. Going from any project where I am logged in to Commons, I am automatically logged in to Commons, so it is possible.
Proposed solution: Automatically log in to all projects if you are logged in to one, no matter which one, like now in Commons.
Who would benefit: All editors who regulary switch from one project to another to make changes/edits.