The biggest variable I found travelling around Europe last year (38 flights in 35 weeks) was which passport queue you had to join. If you're a citizen entering your own country, customs is usually much faster - it's an added variable, not sure how easy (or helpful) it might be to build in.
(My beautiful wife and I were lucky in that we could cherry pick - I was travelling on my UK passport, she on her Australian, so depending on which queue was shortest we either went through together in the UK / Europe line (I'm travelling with my wife) or the Other Passports line (My wife is travelling with me)).
(My beautiful wife and I were lucky in that we could cherry pick - I was travelling on my UK passport, she on her Australian, so depending on which queue was shortest we either went through together in the UK / Europe line (I'm travelling with my wife) or the Other Passports line (My wife is travelling with me)).