Hi Manny,
There are two ways to get around this limitation: one is to put more than one letter in each set. This may work for you depending on the distribution and movement you’re trying to achieve.
A second way is to use more than one instance of Invigorator, so you increase the number of available sets. The only issue with this is the letters from one instance won’t really interact with the letters in the second. This may or may not be a problem depending on what you’re doing.
One way to make everything line up perfectly is to create the ending position of your text animation in one instance of Invigorator. (Do everything to the objects except animating to sets. Then save the invigorator effect as a favorite effect and apply it to another AE layer. Now that you have identical “Invigorated” layers, turn off the visibility of some letters in the first instance and turn off visibility of the remaining letters in the second.
Now go about animating sets in both instances.
Jon