i think it may be a bit more complex than your thinking.
to have a setup like what the OP has in the picture you would need to use something like a map (mesh(mesh), size(float)). I don’t believe maps use indexes do they so you would lose track of the order. If you wanted to use an array then you would have to decide on one variable type. that leads me to thinking a struct for each array index, that way you can store the mesh and the size in one index. from there you would just need to have a script to update the locations of the cubes whenever the size value is changed.
i noticed one other potential issue whilst testing, when i tried to do this using add static mesh component the components would be destroyed if the actor was moved or if a variable changed (changed size variable). now this may be due to something i’m overlooking or maybe the engine version i’m using (4.17) but i figured i’d note it.