I want to first comment on the fact that I appreciate the convenience of automatically logging in. However, I'm now having an issue because I made a quick account while I was in a VC with some friends and now I can't log in to my "actual" account. From some Google searches, apparently the auto login is from a .json file nested somewhere in the game's install directory? Except I can't exactly get there from my Switch, because... Switch. From the same research I've discovered that others who have my issue cannot undo it, because the game will auto log in even after reinstalling the game or deleting save data. (Good luck to me.. lol.)
To elaborate, if I can, what I had ended up doing was because I was in a voice chat, I just made an account real quick with the Switch's login. (Though I do have another existing account which apparently only existed via Steam) so to save time, I just logged in under "Nujuswitch," until I'm done with that and can login to my actual account. So, VC being finished and looking at the website, I'm able to login via Steam, setup a password and username (properly) but, my Switch is unable to properly log out so I can log in with my actual Factorio account. Instead, the login button will automatically log me in under Nujuswitch.
For context, I first got this game on Steam and only recently got the game, again, on Switch. (I'm liking the ability to play on the go/on my computer through the portable system!) However, I would appreciate any support (particularly for Switch...) to be able to log out and back in under my actual account name. I don't need cross save ability, that would be cool though, but cross-play is already way more than I could have ever hoped to experience with the Switch. (As my friend and I were able to test.) My Switch is on build 1.1.74 (build 60256, arm64-ns) if that makes any difference.