Jennifer the Mantra cry is;
...an odd burst of a cry which most babies do as they are settling down. We don't pick up with a mantra cry. Instead, we hold back to see if the child can settle herself. We do pick up with a genuine cry, because its your babies way of saying "I have a need that has to be met".
Each mantra cry is individual, get to know your babies mantra cry sounds like. You'll see it when she's physically overtired, she'll blink and yawn, and her leg and arms fail if she's overtired. She'll also do a kind of "waa.....waa...waa...."sound, like a mantra that repeated over and over, the pitch and tone is the same throughout. It does not sound the same as a genuine cry, which escalates in volume. - TBW -SAYP p235
As far as the clusterfeed & dreamfeeds go, offer as much as he'll take. There is no "set" amount of how much it should be, it's simply to "tank" him up, simply because you want the majority of his calories during the day and you'll eventually want to cut the dreamfeed out. The amount for a dream feed can vary from the amount they take in the day and can often be hit and miss.
HTH's