From what I have observed that type of brace (post to sill in corners)is common in traditional english frames its often curved. You see it also in Normandy france where they have 2 or 3 (echarpes) paralel to each other so it becomes a distinctive visual design element in the corner of the frame as well as structuaral. The german ones (streben??)do go from sill to plate I think there is a picture in the historic timber frame tfg book?
Cheers Jonathan
