Ok, so I am abusing “Event tick” for different actors in a big level, and for sure will have a impact on low spec pc’s.
Any ways/idea to make actors sleep/awake based on a volume or something like that?
I have to admit is impractical to put some “master” BP’s to keep references for various actors to enable/disable them. “Event tick” will still be fired for them, and this will probable solve only the execution part on referenced BP’s.
Overlaps (Trigger Volumes) and Custom Events are your friend!
While writing my third book, I managed to use only ONE Event Tick as opposed to about 20 / 25 in my original project prototype; Any action the player does can send a Custom Event, which is a LOT better peformance-wise then ticking 
What all are you trying to do in the tick event?
Also you could just add a sphere to your actor, and use begin and end overlap to sleep/wake them.
I have a lot of moving objects, more that 200, I’ve made a test with 1000 and practically kills fps, if I fallow “Event tick” route.
If I add a sphere to every moving actor, with a big radius and test overlap against controlled pawn to sleep/awake, you think will be better?