I'm honestly unsure if this is right, but I'm of the opinion that when you upgrade attacks, the Strength upgrade should apply. Obviously the Duration upgrade shouldn't, since you can only attack once per round (barring Force power shenanigans, such as The Force is My Ally or the Unleash upgrade that lets you spend a DP to use it as a maneuver once/session), but am I reading this right?

It applies for all ongoing effects, so yes, it does apply to your attacks

And should you attack twice, for whatever reason, it would apply tout both of your attacks, thanks to the duration upgrade

Thanks! I feel like this should be in the FAQ; I'm sure I'm not the only one who'd be confused. Sure, the wording seems obvious, but...

What exactly make you confused ? Is that the fact that the control upgrade to modify your attack dice is unlocked after ?

Because that has no importance on how the skills interact, only the wording is to be taken in account, and it is pretty clear here

Both the Strength and Duration upgrades would apply when using the Control upgrade to upgrade your combat checks.

Normally, the Duration upgrade isn't applied as PCs typically only get one action per round, but there are talents that can allow a PC to effectively make two (maybe even more) combat checks in a round. So in those instances, the Duration upgrade would be applicable as well.