Having objects in a Array unlockable

Hi there

So i have an array with 2 objects in it so far, and i have it set up so that either one will spawn at a specific point.
However i want one of them to be unlockable by simply hitting a button. I know how to work and link buttons but i just dont know how to make the objects in the array have variables

So: object A spawns from the get go, but when you press the unlock button, object B will have a chance to spawn as well. How would i do this?

The 2 attachments are the 2 ways i know how to make them spawn (I have spawn1 at the minute)

What about creating a struct with the fields: actor to spawn: bp_some_actor, location vector, available boolean.
Have an array of the struct and when you press the button switch the relevant available to true. When it’s time to spawn something, iterate through the array, if available do spawn else nothing.

Does that make sense?