EF_BONEMERGE_FASTCULL is defined as 0x080, or 128.
This effect should be used with EF_BONEMERGE to make an entity inherit its parent's visibility.
To use this effect, including EF_BONEMERGE, turn off SmartEdit mode and add the following keyvalue pair to the entity:
Remember that you can set the effects value during runtime using an entity's
AddOutput input with the input value
effects x (x being any summation of effects flags to enable).
Warning: Using the AddOutput functionality for this, the new value may interfere with an entity's simulation functionality.