I have been reading this thread and I strongly doubt that it is a pan-Boeing procedure. The B744 would be wildly out of safe flight at any sensible CRZ altitude using these numbers.
According to the QRH, at CRZ altitudes not too far from optimum, 2.5* NU & 93% N1 will give a safe speed and close to level flight while you sort out the problem from the QRH. It is worth keeping in mind that the aircraft was flying along nice and stable until whatever the warning was is displayed. Doing nothing is a good strategy for the short term.
I await to see what Boeing actually publishes, if anything, to change the current B744 procedures.