I don’t know of any such functionality in the engine, and AFAIK even UE4 doesnt have it
I guess you’ll have to start adding up the tricks mentioned here
to add to the pool of tricks I’ll suggest using Nathaniel’s suggestion of the array of bots heard by the player, and do your tick-based occlusion reducing it to 1 (or a few) per-tick.
this way more bots only mean more delay in the occlusion checks, but never less performance