Neil Williams wrote:
[1] I remember the reason why I don't do auto-top-up now - you need to
nominate a Tube station to start it from, from which you have to travel
or you end up with an unresolved journey, and I never quite know where
or when I'll use my Oyster next.

This is only true for the first time, to activate auto-top-up. After
that the card will top up at any gate you enter through.