Would I be right in thinking the following ?

If the OP had tacked the whole main triangle before brazing the ST/DT joint, the joint would try to close up (as before) but being restricted from doing so, would put a 'hidden stress' into the structure.

If this is the case, then if the OP forced his misaligned tubes to fit as intended and finished up the frame, would it give the same 'hidden stress' as would be present if he had tacked the whole lot together first?