I did not like the B 17 with a zero setback seatpost. so I traded it away..
the Selle Anatomica might shove back further as they made the rail adjustment range longer,

But I got a composite Fizik Vitesse that Brompton got made, special batch..
with a high clearance rail bend, that seems to work.
it is OK out in the weather.. being not leather..

Have a 30 year old Brooks Pro, on the long touring bike..