I suppose it depends on the school. In my town, it’s a pretty serious commitment. (Disclaimer: none of my kids did DECA but I’ve seen the news stories about their awards over several years.) I think college admissions people will look at a long term commitment to ANY group as a positive sign. especially if the student takes on leadership roles in later years.
From my recollection, only regionals are prior to Jan. 1, states and nations are in March/April. Placing at regionals isn’t difficult, and that would be the only event you could put in a regular decision application. imo, 7th semester grades, application polish, ACT/SAT retake would take priority over an EC you can’t use anymore.
Gosh… those darned ECs that anyone can join. The horror, the horror! of doing something because you find it enjoyable and not because it might look good to some college somewhere down the line.
Let the poor child do DECA if she enjoys it and that should be the end.