Now, if the user logs in again, he's back on the start page of the admin backend. (That's the part I didn't actually realize before.)
I think it would be a huge improvement in terms of usability, if after the re-login, the user would be "forwarded back to where he was working before the timeout" (Hope you get what I mean here.), if that's possible with a reasonable effort of implementation. (Including the world-famous performance pennies, of course!
)YL