It does apply but not as much as the other, more specific, rules already cited.
There is one other outcome then those discussed so far. The RM could declare shooting the target prior to activation a forbiden action; 2.3.1.1. A good example of this happened on a stage I worked at the 2012 Multi-Gun Nationals, sorry I can't remember the stage number might have been 4. On signal pull cord to open a window, engage popper that activates clam shell that is shot through a different port to the right. Window won't stay open unless cord is held somehow. Last two shooters of the first day asked the CRO if shoot target of the clam shell could be shot before activating the target. WSB doesn't say you can't, target is visible on the ground but a pretty tough shot. Both shooters do it that way. CRO calls the RM, discussions abound. How many shot it like this, what are the other options? Only two shot it like this, but it is commonly seen once somebody figures it out everyone starts shooting it that way. Other options are let anyone that wants to shoot it that way do so. Is it a competitve advantage? Hard to say don't think so, unless you are 6 foot tall. Or throwing the stage out, not really the desirable choice. I am guessing that there was discussion with NROI before this decision was made. The next day the WSB says engaging the clam shell before activation is a forbidden action. The two shooters who did this were told of the decision and given the day to reshoot the stage or take a 0. Guess they could have gone to arbitaration. They came back at the end of the day. Both guys shot it faster the second time through.
