One thing that's always puzzled me in the RB's versions is the bit where Hilarion nails Albrecht's identity by comparing the coat-of-arms on Albrecht's sword with the one on the Duke of Courland's hunting horn - which wouldn't, I've always thought, be the same. But reading the original libretto it's finally dawned on me (OK, so it's taken me 40 years, so I'm a bit slow!) that the huntsmen are Albrecht's people, not the Duke's: Bathilde and her father are staying with Albrecht to celebrate the engagement, and he's sent them out hunting for the day without him.
(When I look at the synopsis for the RB version, it actually explains this - so maybe I should read the programme notes more ioften!)
So, what we need is a bit of new mime: instead of just 'What on earth are you doing here dressed like this?', the Duke needs also to be able to say '..when you told us you were spending the day sorting out legal stuff/in bed with a sick headache'.