Regarding me insulting the Level Blueprint - I exaggerate, it sure has its uses. You can use it as a manager if this level has some unique functionality.
If I wanted to choose a random spawner and have it create a monster regardless of the player being close by:
- a new Custom Event in the Spawner blueprint hooked up to the same nodes as its timer
- get the Spawner references:
- this makes the array of Spawner actors, starts a Timer and makes it pick one spawner at random
- we then call the custom event mentioned above
- now the spawners work even if the player is away
- and if we step into the spawner sphere, both timer will run - the one in the spawner and the one in the level blueprint
Hope this helps.