it appears everyone agrees that it should be done right away. but i have a different approach, i feel it should be done gradually. the reason has nothing to do with bb, but everything to do with mvd.
i unload my mvd at wm by getting mo. i bring mo to my bank. both of these actions, if done too frequently, can raise a suspicious eyebrow. thus, its better to space out trips to wm or the bank with mo in hand.
thus, i feel its good to do mvd in the begining of the month, right away. then take a day or two break. during the break, load the bb a little tiny bit.
then when you feel comfy doing the mvd thing again, load that go to wm, go to the bank. perhaps enough time elapsed where you won't get suspected of bad activities.
then do bb, then wm, over and over, you get my drift.
i understand why people do bb right away, because it is so much easier. but i feel its better to spread things out so as to not raise suspicion when you use mvd at wm to get mo that are deposited in the bank.