ZAP TO THE EXTREME!
This strikes me as counterproductive in most cases. That's not to say that more charges won't be brought, but if I'm the prosecution, and I have evidence to get convictions on multiple felonies, I want the defense to know about it during negotiations so they'll take whatever I decide to give them. I don't do myself favors by being coy about the strength of my case or the number of felonies I can get convictions on.They wouldn't publicly lay down further charges at this stage since that would fuck up negotiations and tip their hand.
Likewise, if I'm the defense, and they haven't charged my guy with something, then I'm probably concluding they don't have the evidence yet. If the State says it's gonna charge my guy with more felonies unless he takes the plea, then I'm asking to see what evidence they have so I can advise my client. If they refuse, then they can go fuck themselves--they must not have shit.
So I just don't see how the prosecution does itself favors by essentially pretending its position is less powerful than it is.