This post is from 4 years ago… This can definitely be done in blueprint quite easily and show with several items on the marketplace which now exists.
^ This. The original posts were made four years ago, during which time capabilities for blueprint scripting have changed dramatically.
Four years ago, what FlippedBit wanted to do wasn’t possible through blueprint scripting, so he created a new thread in the programming section where he resolved his problem.
Thats fine, here is the OP’s answer (ignoring the fact that its in the blueprint section, and focusing on the question itself)
Well I took matter into my own hands shortly after my last post and created my own “inject actor on map load” plugin system
These are singleton-like actors that are auto injected into any level that you load in the editor, new or saved map (during editor loading or game play loading).
To get exactly what the OP asked for would require small modifications, but hooking the map load was what the OP was looking for. (without using gameplay events)
These two plugins come with a blueprint library that exposes the singleton-like actors with the nodes:
From there you can call their own functions / get variables ect