A purely personal pilots point of view......
If cotroller'A'clears me to descend to a FL by a specific point,and then hands me over to cotroller'B'who then gives further descent,I will continue to descend at the original rate to make the first restriction.I know that technically its not a requirement to do so,but it just makes a lot of sense to me.Neither controller'B'or myself are aware of why controller'A'set that restriction,so I for one am still going to respect it !