I also recall hearing about some switches being slightly different in length/depth, as this part (or similar one) has been in use in numerous vehicles over the years.
Ahh well there you go, I probably misread/overead the note with the 'she'll be right, she only got one washer'....used to OEM parts attitude!
P.S Hopefully I don't sound like a co*k by saying that but I've had to buy many new parts over a few years, MB so good for their sourcing of original parts I usually go for that and pretty goood price

(well compared to any NZ BMW dealer who knows these parts are all overseas anyway, often on back order and probably more expensive they can't see any more reason. Hhhhm, all comes down to demand. Small country, old bike, we wanna sell the S1000! I wanna ride one!