I was wondering about the possibility of pinning the whole front triangle at once, and brazing all the joints while pinned. I haven't heard of anyone doing this though, so I assume there's a reason it's not commonly done. Maybe stresses in the frame from heat distortion? Although I suspect this would be less of an issue with lugs than on a fillet brazed or welded frame where you have filler metal contracting and pulling in as it cools.