Hello Angelica,
I have spoken with our Development group and they said referencing the same AOF Variable more than once in a rule will cause more time to compile and/or process the rule. This is how our code works. If you are going to reference the same variable more than once in the rule, it is advisable to assign its value to another variable. It is true what you were told.
Thank you,
Kraig Johnson
Sr. Support Engineer, Customer Support
One team, Your Success. Everyday