I've been through all the usual suspects. The problem they all share is insufficient saddle travel. Let's say you want to tune down 3 half steps. The E (or B) string saddle won't move back far enough to get proper intonation. Tuning down 1 whole step seems to be the limit of saddle travel on most bridges, and even then you can't always get it far enough back for proper intonation. Is my only option to move the entire bridge back? Or is there some well-designed bridge I've overlooked that allows proper intonation when downtuned?