Take it back! 
And call it 40 times. Something that dispatchers don’t care about.
Blueprint A works with Light A,
Then in a new design, I duplicate to Blueprint B that uses light B, but then you need to rebind everything.
I sense you forgot about inheritance. You declare dispatchers in the base class, every child already has it. Dispatchers work best when you spawn dynamically.
Half the time it’s about finding the reference, the other half is finding out what communication method works best in a specific scenario.
- dispatchers are efficient and clean but they can also suck at times, are not suitable to all tasks. You need a reference only once and if the object does not exist, it does not matter.
- interfaces are universal but they generalise, obfuscate and make a mess of things - every call is available for every entity, they return default values even when not implemented but called - super scary and hard to debug. And you need a reference every time you call.
- direct comms is direct comms, you get what’s on the tin
You do not settle on one method, you use them all - where it makes sense.
I’m trying to dynamically sync the rotation of a component in Blueprint A with a mesh in Blueprint B.
Both are spawned in my scene at different times.
Probably a job for a dispacher. What spawns them, where, how?