JT,
As you know, consultants don't have holidays, they just have interludes in the work programme! Unfortunately, I missed the Bend as one of ny VSCs (very significant client) required my presence elsewhere.
Yes, the change permitting Vs1g did predate the B763 but postdated the amendment applicable to the original TC. The problem may have been triggered by CAAUK certification requirements, I am not sure. In any case, those students of FAR 25 and its clones will find that the numbers do not add up - Boeing negotiated a slightly different set of ratios and margins with the good ole FAA.
As for the comments about what B744s will do - I think the main thrust of the topic was certification requirements, of which none that I am aware require guaranteed performance in the event of suffering a second engine failure during the take-off sequence if the risk assessment indicates that secondary damage is highly improbable.