Thanks for trying! I’ve found a way to show what your script does. Your way is probably more efficient and I’ll use the For Each Loop, but I found out the problem lays in the Timeline. Here’s an animated gif: (it should only repeat 10x)
While working on my problem, I found the Timeline cannot work in parallel. Even is you create a Function and pass the values. By the way Function don’t accept Timeline but you could create an external BP, put it in the scene and call a Custom Event via "Get All Actors of Class → BP_Animation). It will fail… 
Animations cannot overlap.
I’m trying to have multiple instances of BP_Animation and calling unique one/currently not in use. I think is an ugly solution but I have none other.
I’ll let you know is it works. If you have another idea, let me know.