On preps and charges, since charges seem to be a mechanic (one that I think sounds intriguing and useful) that isn't wide spread, what is the experience with a type of prep that doesn't effect the prep-determined effect, but other side effects?

As an example, one might wield a weapon that releases a powerful blast of energy much like a ballistic. When he preps (charges) it isn't to increase power, like the other mechanics, but, and this is for the example, to allow the charging of a field to reduce blowback from the energy shot. No charge or prep will send the user back, perhaps cause concussion damage, while prep allows them to execute the blast safely. A similar mechanic exists in the character I am transferring.