Yes. You can use frozen lime juice concentrate and Eagle Brand and call it a key lime pie, but it is a lime pie, not a key lime pie.
I think as long as it has 1/54th lime in it, it qualifies.
Add 1/3 cup of lime juice to the judge’s recipe....viola! Really delicious!
Key limes are different from regular limes, by the way. I wouldn’t think of adding regular lime juice and calling it a Key lime pie! The heavens would open and my mother would chastise me sternly.