The specifications are the same for all oils, regardless of basestocks.
MRV is the ability of the oil to "fall" back into the pickup to replace the oil that has been pumped into the engine oil galleries.
CCS is the drag that's applied to the engine during starting because of the friction of the oil between engine components.
Pour point was formerly a part of the "W" testing but was dropped as being meaningless, and not representative of either the startability, nor the pumpability of the oil...so all the pour point tests of 5W at -40C are similarly meaningless, unless you are planning on changing the oil and getting it out of the bottle at these temperatures.
One thing, however.
Oils are allowed to "slip" a grade in the in service testing. So a 0W oil that slips to the viscometrics of a 5W in service still "passes".
This is where I personally believe (note, I have no proof) that synthetics are better in CCS/MRV, they are (in my belief) more likely to stay in their original grade.