Hi,
This action is on the Ecosystem (IsVisibleInCameraFrustrum). I just updated it to remove as much GC as possible, it will be even better starting 2017.3 as Unity made a GC free version of the frustrum planes api command.
So update the action from the ecosystem and use that one instead of the one attached to the first post of this thread.
Let me know if you see an improvement.
Bye,
Jean