Since we're talking about force powers here, I thought I'd posit a theoretical situation. It's only theoretical, because I don't think it can happen with the current batch of force powers.
Say, you have a force ability that lets you add force pips as successes to a skill roll. I believe the Enhance power has several of those, as does Influence. Now, let's say there's another force ability that let's you do the same thing and there's an overlap in the skills that can be augmented. Does this mean that you can make more than one power check for the specified skill?
In other words, let's say you have the second Control ability of Influence that lets you make a power check for a batch of social skills (Coercion, Charm, Deception, etc). Then, in some other supplement, they include a power that allows you to do the same thing with another batch of skills, but, say, Charm is in both abilities. Does this mean you can make two power checks for Charm and add your light pips as successes? So, if you have a force rating of 3, does that mean you can roll 6 force dice, since you have two separate abilities that affect Charm (assuming you don't have any dice committed to an ongoing effect)?
My guess would be that you can only roll it once and that they'll never include any powers that have overlaps like that. But...
My main impetus in asking this is that I'm going to be including force dice for skills in an upcoming version of my character generator. I'm only going to show a single force dice, since that would represent a force power check with however many dice you have available to use. However, if you can make multiple checks, then I should be allowing for more than one force die to be displayed, each representing a power check.