Stamatis,
Well, I`m only guessing here. The object is a level change during the CRZ part of your flight. As far as a CRZ descent goes, it`s obvious, as the default TGT SPD in any descent mode but the CRZ descent seems to be a whopping 273 kts IAS. A CRZ descent will keep you at your M.78, which is what you really want.
As for the CRZ climb, I would say more or less the same, as the object here also, is the econ CRZ speed, and not so much the factor best climb speed, which is probably just left out of it. Most of the time it`s not more than 4 thousand feet anyway.
But, again, I`m only guessing.